Friday, February 17, 2017

The Thousand Faces of Winter

The woods were filled with light and shadows. Blinding white and midnight blue painted the ground, while the breeze blew fairy crystals of snow through rough, brown trunks. Although Lois Nestel (the Museum’s first naturalist) may not have fancied my mode of travel (fat bike), she certainly would have appreciated this scene on the beautiful Seeley Hills trails.

Lois had her own favorite ways of getting out to enjoy each winter, and she wrote about the snowy landscapes she cherished in her newspaper column, “Wayside Wanderings.” During the Museum’s 50th birthday year, I’m sharing some of her stories again. It’s a relief—a deep cleansing breath—to escape from our current, fast-paced news cycle into her gentle and reverent words.

“Winter has a thousand faces;” observed Lois, “each of us is free to see the face we choose. For example, the colors of winter are subtle and transient. Nothing is as it seems. The snow is white, it is true, but it is also endless hues and shades depending on the light, the type and quality of snow, and even more on the eye of the beholder.”

“Under leaden skies the snow appears dead white or pearly toned with shadows that are slate and steel. Sunrise can turn open spaces to rose and palest gold shadowed with lavender and violet; mid-day brings the clearer blues, and the evening sky may add a depth of tone to morning hues.”

“Frost flakes caught in morning sun outshine the jewel treasures of the world as prismatic reflections bedazzle the eyes with brilliant sapphire, topaz, emerald, and ruby that change with every movement and finally fade with advancing day, as do the rainbow-tinted sundogs that accompany a chill morning sun.”

“Moonlight on the snow brings shadows traced in indigo against the cold white flame of diamonds. The blue-black velvet of the night sky, studded with cold, blazing stars will often show the aurora borealis as wavering, tattered banners or as moving spotlights against the northern sky,” wrote Lois.

Recently, I caught my own breath at the shining magic of the near-full moon as it played peek-a-boo among the trees. Lois’s words floated through my consciousness. Letting my skis find their own way in the tracks, I swiveled my head as far as it would go to enjoy the moon’s glittering path. Later that night, the luminous glow—amplified by snow—fostered insomnia.

Lois summed up snow this way: “However you see snow, as a burden to be borne or as a base for winter sports, see in it also the incredible beauty beyond the power of man to duplicate or even to describe.”

In the Northwoods, trees are as much a part of the winter landscape as snow. They complement each other, and accentuate the other’s beauty. Lois appreciated each one in her own whimsical way.

“Had I been one of the druids of old,” she began, “I believe my worship would have been, not for the mighty oak, but surely for one of the evergreens. While other trees have dropped their ruffled gowns and stand in shivering nakedness, the evergreen reaches out with well-clothed arms to offer shelter from the cold. We would be bereft without this royal family of the northern climes.”

“Here stand the spruces, maids in waiting, dark, slender, dancers of the skyline; and here the balsams, reserved aristocrats, rich in their own perfume and decked with icicle and frost jewels. Here are the tough, gnarled jack pines, outcasts and black sheep of the family, fighters for their share of the earth. What they lack in grace they make up in sheer tenacity.”

“Here are the hemlocks, full of queenly grace and serenity from seedling to massive and dignified old age, replenishing the earth beneath them and pouring forth their largess in multitudes of cones to benefit the wildlife. Here too the sinewy cedars, crown princes of the swamplands and benevolent overseers of the delicate orchids.”

“And here, head and shoulders above the rest, stand my beloved white pines. Like lanky, callow youths in their early years, they develop the symmetry of handsome adulthood and in the fullness of their years are craggy, unconventional and full of character. There is strength in the clean lines of great limbs and tenderness in the soft-whispering blue-green plumes of needles. As I see them now, mantled with snow, it is as the cloak of ermine tossed carelessly across the shoulders of the king. Towering in stately dignity, no other tree adds such distinctive beauty to the sylvan scene.”

“If I were a druid, to this tree would I bow down. But as I am not, I can only gaze in awe and admiration and think, ‘What wonders God has wrought!’”

We are lucky to live where snow and trees surround us. Perhaps we should all take a cue from Lois and spend a few moments each day gazing with gratitude at our extraordinary world.

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is open through March 11.

Friday, February 10, 2017

Hunt for the Wondrous Water Bear

 “They exist in some of the most extreme habitats on earth, from the deep sea trenches to mountaintops and Antarctica. So I thought, maybe I could find one in Wisconsin, too!”

Kaylee Faltys, the Museum’s new Curator, sat down with me recently to talk about her hunt for the wondrous water bear.

“To know about something for eight years and then finally see it was thrilling!” said Kaylee. She’d first learned about water bears in an aquatic invertebrate ecology class as an undergraduate. Water bears, also known as tardigrades and moss piglets, are aquatic, microscopic, eight-legged animals, and are thought to be the most resilient animals on earth.

“They are the ultimate honey badger!” joked Kaylee, referring to a viral video from 2011 about an African mammal who was named “The World's Most Fearless Creature” by the Guinness Book of World Records. The catchy tag line from the video was “honey badger don’t care.” While honey badgers don’t care about venomous snakes and stinging bees, water bears don’t care about extreme temperatures, x-ray radiation 1000x the lethal human dose, desiccation, the vacuum of space, and pressures higher than you’d experience in the deepest part of the ocean. Among scientists and naturalists, water bears have developed quite a reputation for being tough.

“They’ve survived in outer space! They seemed too good to be true,” said Kaylee, “so I didn’t think I’d ever see one in real life.” But when Kaylee started researching lichens for the Cable Natural History Museum’s new exhibit, an idea started developing. Lichens are leaf-shaped organisms composed of both fungi and algae that grow prolifically on tree trunks and other surfaces. They provide habitat for a multitude of microscopic life. “Lichens are one of water bears’ classic habitats,” she said, “and I started thinking about how cool it would be to actually try to see one.”

So, armed with her trusty pocket knife and bundled up against subzero temperatures, Kaylee ventured into the untamed wilderness—of the Museum’s backyard. After slicing a small patch of lichen off the tree, she brought it back inside and soaked it in room temperature water overnight. Kaylee hoped that the frozen water bears would come back to life.

Despite their crazy survival skills, water bears aren’t considered “extremophiles.” Those critters actually seek out and thrive in extreme environments like deep sea vents. In contrast, water bears have learned to simply endure. Their strategy involves going into a state of “cryptobiosis” or extreme hibernation. All measureable metabolic processes stop. Their water content can drop to one percent of normal. The organism seems dead, but the condition is reversible.

Getting rid of water is a key to their survival. Water expands and contracts drastically as it freezes and thaws, which can damage cells. If any water molecules are left as a water bear dehydrates, a sturdy sugar called trehalose physically prevents them from rapidly expanding as a result of temperature changes. That’s not all. Flexible, shapeless proteins rearrange themselves into solid biological glass as they dry out. This bioglass wraps other important proteins and molecules in a stiff, protective envelope that holds them together. The bioglass melts as the water bear rehydrates, and everything starts moving again. These adaptations are so effective that water bears have survived more than 30 years in their state of suspended animation called a “tun.”

Back in her office, Kaylee put a little bit of the damp lichen on a microscope slide, covered it with a slip, and started searching around the edges for signs of life. Almost immediately she spotted a little wiggler. Although it was almost completely translucent, its chubby, segmented body, four pairs of stubby legs, and two eye spots were readily visible. “The little guy moved fast,” she exclaimed. “If I looked away he was gone!”

“This is a milestone in my scientific life,” philosophized Kaylee, who just began her dream job as a museum curator after receiving a master’s degree in biological sciences from South Dakota State University. “It made my day.” And now Kaylee is hoping to share her excitement about these amazing, oddly cute little creatures. “I’m planning to hold a Tardigrade Treasure Hunt program this summer, to help people discover the amazing varieties of life that exist out of sight in our own backyards.”

Tardigrade, by Schokraie E, Warnken U, Hotz-Wagenblatt A, Grohme MA, Hengherr S, et al

Special Note: Emily's book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at Listen to the podcast at!

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: "Nature's Calendar: Signs of the Seasons" is open through March 11.

Friday, February 3, 2017

Foggy Fen

Mystical fog hung thick over the fen, and droplets of water glistened from the tip of each evergreen needle. Dark, craggy sculptures of black spruce trees faded into the mist with eerie calm; their silhouettes stark against a melting snowpack. The Namekagon Fen State Natural Area is a beautiful place in every season, even when March comes in January.

It seems like only yesterday that the dripping droplets came from sweat glistening at the tip of my nose, and we all squinted into the sweltering, late-July heat. On that visit, I brought along a TV crew and four teenage cast members to shoot an episode of “Aqua Kids” for public television. The show aired in November, and is now posted to their YouTube site ( Watching the video, my toes remembered how warm the surface water on the bog felt, and how cold the bog pole remained when we pulled it up from 20 feet below the surface. We never found the bottom, but we did discover where the deep cold of winter hides.

The vibrant greens of July were nowhere to be seen on this most recent visit. Under the dim light and fog, the scene was etched in grayscale. With the Aqua Kids, I’d dissected a red-veined pitcher plant leaf and poured a mass of squirming larvae out of its miniature ecosystem. Those leaves are buried now, but the tall, dried stalks of their flowers poke up above the snow like periscopes searching for spring.

Life was humming then. The fen is silent now, and still. Until you look closer.

Shifting my focus from the faded distance, I noticed a smattering of black specks on the snow at my feet. Snow fleas! As I stared—trying to bring them into focus—they vanished one by one.

Snow fleas (also known as springtails) aren’t even insects. They do have six legs, but a lack of wings, simple instead of compound eyes, differences in molting, and a special mouthpart for drinking, set springtails apart from true insects. When startled, a snow flea releases a clasp, and a forked appendage snaps open against the ground. Launching up to 100 times their body length in an uncontrolled flight, they appear to vanish into thin air.

Springtails are unbelievably abundant in moist habitats, and happily live in the soil and leaf litter year-round. Just one or two species come out on the snow, though, and they have a unique protein that works as antifreeze down to about 21 degrees F.

While crouched low and peering at snow level to watch the snow fleas, we finally spotted a dash of color. On a snow-free hummock under the thick boughs of a black spruce tree, lay a ruby-red cranberry on a bed of emerald moss. The fog seemed to lift for a moment as the tangy juice burst onto my tongue.

Snowshoeing on the semi-frozen, snow-covered surface of the bog was slightly easier than wading through the drifts of soggy, summer sphagnum moss. Occasionally, though, we broke through into a snow cave propped up by a scaffolding of leatherleaf twigs. At the bottom of each hole, and often at the bottom of our footprints, was a little pool of slush.

I saw one collapsed tunnel of a meadow vole, but not more. In a normal winter, with cold temperatures and plenty of fluff, small mammals seek refuge in the subnivean zone at the boundary between earth and snow. This melt turned that magical world into a slushy mess capped by ice. I’m not sure how the former residents will manage.

At least one of the subnivean citizens came to the surface. The small black dot resolved into an eight-legged spider on the snow as I bent closer. It was hard to see details in the low light, but I tried for an extreme close-up with my camera. Later, on the computer, I zoomed in to discover hairy legs and a dew-covered abdomen.

Wolf spiders are common predators on the forest floor all year round. They overwinter as adults and sub-adults, and continue their lives in the subnivean zone. The cold doesn’t seem to slow them down as much as it slows down their insect prey, which gives them a hunting advantage. In the perpetual twilight under the snowpack, wolf spiders have another advantage. Two large eyes (in addition to two medium and four small eyes) give them excellent vision. A layer of special tissue in their eyes improves their sight in low light, and also results in eyeshine from probing flashlights.

The dark bodies of spiders on the surface of the snow occasionally absorb so much heat from the sun that they begin to melt themselves into a divot. There was no sun today, but fog had condensed into sparkling water droplets on everything in the fen—including each of the spider’s bristly hairs. With the long view obscured these days, beauty must be found close at hand.

Special Note: Emily's book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at Listen to the podcast at!

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: "Nature's Calendar: Signs of the Seasons" is open through March 11.

Friday, January 27, 2017

Grouse House

Two perfect tracks paralleled a sinuous curve of the frozen Montreal River. Back at the ABR ski trails near Ironwood, MI, I was enjoying a leisurely classic ski while my friends all zipped around the wider trails on their skate skis. The morning was perfect: blue skies, bright sun, and temperatures rising quickly out of the teens.

Here and there, a few animal tracks stitched their way across the trail. They were coyote, maybe, or red fox. Then a bigger depression beside the trail caught my eye. Was that a sitzmark from a clumsy skier? Not quite. Like an upside down exclamation point, a yard-long, foot-wide trough ended at a small bridge of unbroken snow. Capping it off was a chicken-sized snow angel.

Naturally, I slid to a halt and gingerly backed up in the tracks to get a better look. I also pulled out my phone and turned on the camera. (I’d rather use a good camera, but I prefer to carry my phone!) This was the best example of a ruffed grouse’s snow roost that I’d ever seen!

Grouse are exquisitely adapted to winter. They grow their own snowshoes in the form of fingernail-like projections on their sides of their toes. Extra feathers on their beak and legs provide insulation where it’s needed. And when their fluffy body feathers aren’t enough, grouse use the snow like it’s a cozy down comforter.

Once there are 10 or more inches of snow on the ground, grouse will dive or burrow into the fluff and spend the night in an air-filled tunnel. Temperatures under the insulating snowpack often reach a pleasant 32 degrees F. No matter how cold it gets, the snow roost rarely drops below 20 degrees F. Research has shown that grouse don’t need to really speed up their metabolism to keep warm until the temps dip below 25, so the snow roost provides them with significant energy savings.

I could see the grouse’s sleeping nook begin where the trough ended. Skiing forward and looking back into the tunnel, I spotted a pile of about a dozen macaroni-shaped scats in the shadows. Yes, I took a picture of the scats! They represent another purpose for the snow roost. In winter, grouse subsist on tree buds and catkins. Trembling aspen buds seems to be the most nutritious—and grouse prefer them—but the buds and catkins of bigtooth aspen, birch, alder, willow, hazel, and ironwood also provide sugar and protein.

There are two main problems with eating tree buds, though. First, they take a lot work to digest. To address this problem, grouse have a muscular gizzard with added grit that grinds up the woody material. From there, the softer materials enter the caeca. These two extra-long pouches contain specialized bacteria that can digest cellulose and absorb more nutrients before the food exits their digestive system. Waste from the caeca ends up as a dark, shapeless plop, while the woody materials become cylinders of molded sawdust like those I found in the roost.

The second problem is that eating buds in the leafless treetops exposes you to the hungry eyes of predators. As many of you know, grouse meat is quite tasty. A grouse’s solution is to eat an entire day or night’s worth of food in about 20 minutes. They store all that food in their crop—an expandable sack at the base of their neck—and then find a safe spot to digest their meal. A snow roost shields grouse from the piercing eyesight of hawks and owls, as well as the sharp noses of foxes, coyotes, bobcats and fishers.

With only my lowly human senses and tendency to daydream, I’m sure the snow roost would have completely concealed its resident from me. If I’d skied by earlier and been the one to flush out this grouse, I would have been completely astonished by the flying snow and flapping wings.

Snow roosts aren’t just an interesting tracking story to read in the snow, though. They are truly a necessity for these birds’ ability to survive the winter. Thin or crusty snow—unsuitable for roosts—makes their brown feathers more visible than no snow at all. While the deep freeze of last week may have challenged our thickest mittens, it also provided perfect conditions for grouse to hide. The balmy temperatures of this week may feel pleasant on bare skin, but they are wrecking the snow for grouse and skiers alike. A 2008 study in The Wilson Journal of Ornithology found that about 17% of the variation in grouse populations is controlled by snow conditions of the previous winter. Deep, fluffy snow equals more grouse. Crusty snow results in a higher mortality rate.

As I skied on (and on, and on…for a total of 50k of Birkie training in two days!) the tracks of weasels, hares, mice, wolves, deer, and squirrels crisscrossed the groomed trails. Just like the grouse—and the dozens of other skiers out on the trails—they have adapted to winter. If you know how to take advantage of it, good snow can be a real boost to your survival.

Special Note: Emily's book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at Listen to the podcast at!

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: "Nature's Calendar: Signs of the Seasons" is open through March 11.

Friday, January 20, 2017

A Winter Walk with Lois Nestel

As the Cable Natural History Museum enters its fiftieth year in existence, we find ourselves pausing to remember the past as well as dream for the future. In particular, I find pleasure in contemplating the legacy of Lois Nestel, the founding naturalist, director, and curator of the Cable Natural History Museum. Lois was a talented, self-taught naturalist, artist, and taxidermist. Examples of her accomplishments populate every corner of our modern museum building. Her legacy is strong in the work that we do.

I never met Lois, but every Friday I feel a particular kinship with her as I send my “Natural Connections” article off to the newspapers. Lois initiated the tradition of a weekly nature column provided by the Museum, and did so with a gentle, reverent, poetic style. Her column was titled “Wayside Wanderings,” and the articles were compiled into two small volumes in 1975.

One of my favorite authors, Sigurd Olson, provided the introduction to Lois’s first volume. In his characteristic style, Sigurd wrote: “With the eyes of a naturalist, artist, and poet, season by season she has recorded the miracles she found there, miracles that epitomize the truth that we are all part of nature; that because of our primeval background we hunger for simplicities of the past, the beauty of flowers, trees, and animals. Her essays build awareness and open the eyes of children to a world of wonder and delight they may not have known before.”

While I never had the privilege to go on a walk with Lois, her words transport me into a forest that feels absolutely timeless. “It was a perfect day to walk in the woods,” she began, and I’m sure you can imagine it with her. “The first snow had been followed by a warm, sunny day so that the packy snow went “squdge, sqwudge” under foot. Though well-grown and diversified, this forest still bore the scars of long-ago logging. Skid roads, now barely discernible, meandered down wooded slopes toward bogs and ponds. They were primarily game trails now, and little more than occasional cuts and fills were left as reminders of man’s intrusions.”

“The light covering of snow was pierced by winter ferns, ground pine, and club mosses that were unbelievably green by contrast, and where the evergreens were thick the duff was richly brown.

Except for the distant chattering of a couple of squirrels the woods were silent, but the soft snow carried telltale marks that indicated an abundance of unseen life. Where birch trees had fallen and the wood long since crumbled away, the durable bark remained in long crumpled tubes and in and out of these ran the twin dimpled marks of weasels, these often overlaid upon the dainty tracks of mice and voles.”

“A hollow log had housed a porcupine, his droppings and a quill or two inside and outside; where his shuffling feet had pressed the damp snow down, the dye from decaying leaves had turned it yellow-brown. Squirrels had hopscotched from tree to tree and the shards of thousands of hemlock cones were evidence of how busy they and the birds had been.”

“As the trail dipped toward the bog it was crisscrossed by rabbit tracks. Here too, silent as a shadow, a raven, gliding into a pine top, vanished as if it had never been. The tracks of a coyote followed the trail for a while before veering off in the midst of a thick growth of young balsams. Just brushing against these balsams in passing left a scent on clothing that lasted for hours.”

“Woodland ponds were covered with skim ice, but the rivulets draining them still ran free, and along them were myriad small tracks too blurred in the wet snow to be identified. Like unpatterned cross stitching, binding the landscape together, were the tracks of deer of various sizes and even in this shallow snow the toe drags were often apparent.”

“These were some of the things I saw, but how much did I miss? How many unseen eyes watched me? There is never time to peer into every hold, under every flap of bark, behind every stump and tree. The only tangible reminder I brought back was a handful of tamarack twigs with their dainty cones, but long after these are gone the pictures in my mind will live.”

How lucky we are that Lois wrote down these accounts of her wayside wanderings, so that the timeless images can live in our minds, too. Lois accomplished many great things over the years, but perhaps one of the most valuable is her ability to bring us into the woods with her. May the peace of her forest walk stay with you throughout your day.

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is open through March 11.

Friday, January 13, 2017

Multi-species Sledding Adventure

The torrential rain on Christmas Day was really a bummer. At my parents’ house in northeast Iowa, we had thunder and ice as well. Once we’d finished Christmas dinner and started opening gifts, though, the weather outside no longer mattered. As the semi-solid drops beat against the garage doors, we drowned it out with the tapping of a hammer on geodes.

The day after Christmas brought better weather, and three kids (well, four if you count me,) high on sugar cookies who needed an outlet for their energy. On went the boots, snow pants, jackets, mittens, and hats. Out came the rainbow of sleds and one snowboard.

Surprisingly, the snow was perfect. Just a thin layer of icy granules blanketed the paths Papa had mowed through the prairie, but that was enough. The sledding hill required no packing, no snowplowing through deep fluff to create a run, and no spray of loose flakes flew up in your face or down your neck. Walking up the hill was a breeze, too, without post-holing on every step.

After a few runs down the old fence line, parallel to a crumbling sentry line of dead elms, we switched to a path cut diagonally across the hill. I loved it. For some reason, I could maintain a straighter line on the side slope, and a sharp drop at the end provided just the right amount of added excitement. Also, I’ve always maintained that sledding is more fun when you yell.

Hiking back up brought even more excitement. There, in the middle of the mowed path, just below the house, was a line of large, 5-toed tracks. I had Zac (age 7) put his gloved hand in one: perfect fit.

Obviously the snow wasn't on a wall, but I can't get the program to allow this photo to upload horizontally!

Had I been in Wisconsin or Minnesota, my first thought would have been fisher. Animals in the dog and cat families have four toes. Weasels, bears, and raccoons have five. But that large weasel doesn’t live in Iowa. As I followed the trail of the 5-toed animal looking for more clues, I came upon a well-preserved pair of tracks—the first one short and roundish, the second one elongated like a child’s foot. I stared in disbelief and shook my head. Bear? Bear! In Iowa?

It’s actually not out of the question. Although Iowa is part of bears’ historic range, like many species, they were pushed out as the land became more settled. Just last June, though, my friend Brian Gibbs spotted one about 30 minutes from our sledding hill, and the Iowa DNR confirms about five black bear sightings a year. The working hypothesis is that as populations in nearby Minnesota and Wisconsin grow, antsy young males travel farther in search of food and females. I like the idea of my new Wisconsin home providing species to my old Iowa home.

I wasn’t sure how the kids would react, but I had to tell them. “I think these are bear tracks, guys!” I said, and we all admired the tracks for about two seconds. Then the sledding resumed, and soon the perfect tracks were obliterated. Oh well.

After sledding, Zac and I found Papa in his workshop and announced our discovery. We went out for a second look. The three of us picked up the 5-toed tracks at the bottom of the hill, and started following their trail. All the tracks seemed shorter now, like the bear had four front feet. The trail wasn’t very wide, either—not like a broad-chested bruin. And then, across a straightaway, the messy trail resolved into a neat, two-by-two bounding pattern leading away from a trough pressed into the snow on the hillside. The bounding is classic in the weasel family. The trough clinched it: otter. In winter, their favorite gait is run-run-run-sliiiiiiide, and I couldn’t help but smile at the fact that this otter also was sledding down our hill.

While otters, like bears, were extirpated from Iowa, otter reintroduction efforts began in 1985. Live-trapped wild turkeys were shipped from Iowa to Kentucky to help its restoration program. Kentucky sent cash to Louisiana, and Louisiana shipped otters to Iowa. In total, 345 otter were released in Iowa between 1985 and 2005. Today, the population is stable enough for a limited fur harvest.

Overland travel is not out of the ordinary for otters as they navigate between watersheds. They can travel up to 26 miles in a day, with 5-6 miles being average. Females and their young stay together in family groups, and males will form their own groups, too. We followed the tracks back up the hill, across the road, through the end of the orchard, and to the edge of a briar patch on the bluff above the Turkey River. We stopped there, confident now that there were actually two otters, and that they were headed to the river for a fishy snack.

Mystery solved, tired and warm from sledding and our hike, we headed away from the river, looking forward to a non-fishy snack.

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at Listen to the podcast at!

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is open through March 11.

Friday, January 6, 2017

Rocks in Our Socks

What did you have on your list when you climbed onto Santa’s lap this year? If you were one of my brother’s kids, you asked for rocks. “Anything else?” Santa pressed on. Rocks and dirt. Kids after my own heart! We are the Stone Family after all. While Santa may not have delivered, Auntie Em and Grandma did!

The dirt is a relatively new request. Derek, 12, has been honing his gold panning skills, and wanted a new batch of Pay Dirt—complete with flakes of real gold—to pick through.

The rocks are a different type of treasure. Somewhere along the line we introduced the kids to “crack your own geodes.” These bland-colored, roundish rocks look positively dumpy on the outside. Whack them with a hammer, though, and they split open to reveal an airy chamber lined with sparkling crystals. What’s not to love about a tradition that includes hitting and breaking things, the joy of surprise, and sparkles all in one?

This year I wasn’t expecting much. The geodes I purchased at our Museum Shop were sallow, plain, and small. I was worried they’d be duds. Derek wasn’t discouraged, however; in his experience, these boring-looking ones have produced the best crystals. I brought four geodes, hoping that Isaac, 14, our original geode cracker, would put down his smart phone long enough to break his own. No such luck. He’s now a power tool addict waiting for the day when he owns a diamond saw and a way to hold the rocks for slicing. When that happens, watch out! Every rock in their extensive collection will be sliced open, anticipating the discovery of some spectacular inner beauty.

The three younger kids and I put on shoes and safety glasses and headed into the garage. We rummaged on Papa’s work bench until we found a hammer and chisel, and let the cracking commence.

Derek is the lead rock hound now, and he cracked the first one. It popped open easily, revealing a delicate lining of clear, glittering, crystals. “Ohhh and Ahhh,” we exclaimed appropriately. He also cracked Isaac’s geode, and the kids dutifully set it aside for their big brother after admiring the sparkles. Next, Zac, 7, the rock cracker’s apprentice, took his turn. The geode rolled around a bit under his tentative hammer, and Derek bravely helped him out by holding it steady. His fingers survived! A crack formed, and one more gentle tap split it open to an admiring chorus. Somehow, the anticipation and revelation never gets old. After Derek helped Zac’s twin, Kylee, split hers, too, they all trouped back inside to show Grandma.

Derek’s prediction had been correct: these unassuming geodes all held beautiful crystals, and the kids declared this the best round of Christmas geodes yet!

Curious as to where these splendid geodes came from, I looked up the purchase order. “Moroccan geodes” was their exotic title. This little country at the northern edge of Africa hasn’t seen a glacier in ages, so the rocks there have had time to weather at the surface. The region boasts some cool geology. Morocco’s geodes were formed in basalt—just like our Lake Superior agates. But the photos of Moroccan basalt look nothing like the glacier-polished North Shore. The African rock is crumbly and brown from ages of oxidation and weathering.

Geodes occur closer to home, too. They are the state rock of Iowa! The epicenter of Iowa geodes is in the far southeastern corner, in a 35-mile radius around the town of Keokuk, including parts of Missouri and Illinois. This world-renowned site sits on the lower Warsaw Formation, which was deposited as mud in a shallow sea 340 million years ago, and lithified into shales and limestones.

It doesn’t matter if geodes form in basalt or limestone; they still need a cavity to start with. The holes in basalt were created when gas bubbles formed in the cooling lava. The holes in the Iowa limestone have a more complicated origin. They began as concretions, which are the opposite of geodes. Concretions formed when minerals hardened around some nucleus in the mud, creating a nodule. After the chemical composition and acidity of the surrounding water changed, a cryptocrystalline type of quartz replaced their outer shell. Next, the inner, more soluble minerals of the concretions dissolved and left a hollow space. Finally, over thousands to millions of years, mineral-rich groundwater percolated through the space and precipitated sharp-angled crystals of quartz from the walls of the cavity inward.

Sometimes other minerals will join the mix and expand the color palette. As in agates, these colors occasionally form concentric bands. The difference between agates and geodes is that agates are created when cavities in the rocks are filled with patterns of colorful cryptocrystalline quartz, while geodes grow visible crystals (not always quartz) into a hollow center.

In any case, getting rocks in your Christmas stocking can be a pretty fun tradition. With the Stone kids, I think that even a shiny black lump of coal would be a treat!

Special Note: Emily’s book, Natural Connections: Exploring Northwoods Nature through Science and Your Senses is here! Order your copy at

For 50 years, the Cable Natural History Museum has served to connect you to the Northwoods. Come visit us in Cable, WI! Our new phenology exhibit: “Nature’s Calendar: Signs of the Seasons” is open through March 11.