Tracking Down Minnesota’s Lost Coast

Photo by Ryan Rogers

In late June, when North Shore campgrounds fill every night, my girls and I leave home in search of a freshwater sea that dwarfs the Great Lakes. For a week, we’ll road-trip lonely highways through northwestern Minnesota along the lost shores of Glacial Lake Agassiz. By the time we reach our first night’s stay at Big Stone Lake State Park, on the South Dakota border, the 90-degree heat will have rendered Ella, age 6, and Grace, 11, sweaty-browed and surly.

In the park’s shady and mostly empty campground, I unwind from the drive by listening to orioles sing and gazing across Big Stone Lake at pretty hillocks furred in wild grass. Big Stone Lake is the headwaters of the Minnesota River, though its long valley was gouged by the Glacial River Warren, the torrent that drained Lake Agassiz. Lake Agassiz itself began a short way north in the hamlet of Brown’s Valley, where we drive in the morning.

Photo by Ryan Rogers

Brown’s Valley is a dry gap between the Red and Minnesota rivers. On the north side of town, water flows toward Hudson Bay, while on the south side spillage seeks the Gulf of Mexico. For millennia, this natural bridge for westward travelers obviated the need for river fords and served as a gathering place. Even before then, as the last ice age waned, meltwater dammed up at Brown’s Valley and formed Lake Agassiz, bigger than any freshwater body presently on earth.

We eat sandwiches at Sam Brown Memorial Park, named after a local character known as the Prairie Paul Revere. An old pickup parks, and out steps a short man with a formidable salt-and-pepper mustache. Richard Johnson asks if we want to see the town’s museum, housed on-site in a weathered oak log cabin. I sure do. Some small-town museums resemble marginal flea markets. Others house singular artifacts folksily curated. This is the latter type. Johnson shows us sepia photos revealing an extinct landscape, the horizon-spanning tallgrass prairie. A glass case contains gorgeous Dakota beadwork, including a knife sheath he claims contains 1 million beads.

Photo by Ryan Rogers

Richard points out a wooden wheelchair that belonged to Sam Brown, the son of a Dakota chief’s daughter and the town’s namesake white settler. In 1866, Brown undertook a 150-mile horseback ride to intercept an erroneous message that could have sparked another war with the Dakota. The 21-year-old succeeded but got bushwhacked by a spring blizzard that froze his legs. He never walked again.

On our second morning, we drive north on a pretty route side-walling the valleys that cup the Big Stone and Traverse lakes. Traffic is sparse, and the occasional opposite-lane driver usually waves. We look for breakfast in the tidy town of Wheaton, walking by the Rusty Anchor Bar and Fuzzy Cheeks Boutique inbound for the Country Corner Cafe, where the waitress dumps fresh coffee in my mug whenever it drops below three-quarters full. I eavesdrop on the longest table in the restaurant, populated by a changing cast of locals. They discuss the price of a bale of hay, currently $12. When my bill comes, it’s about two bales, or a modest $25.

We head toward a series of Agassiz beaches outlining the lake’s varying levels over several thousand years. Back home, I’d met with a University of Minnesota Duluth geology professor for tips on finding Agassiz. Howard Mooers indulged me with lidar imagery depicting the littoral mounds of wave-deposited sand as prominent ridges, warning they’re subtler in person.

Vectoring northwest on Highway 9, we reach the first beach at Herman, a small town best known for its 1990s campaign to attract mates for its 78 bachelors. Oprah Winfrey profiled the effort that led to a couple of marriages. The town is also home to Agassiz’s highest beach, described by geologist Warren Upham, who named Lake Agassiz, as “a remarkable deposit of beach gravel and sand” like you’d find along the ocean. Jacked on coffee and envisioning Duluth’s Park Point dunes rising incongruously from farmland, I shout at the girls, “Look for the beach!” I’m manically scanning the pancake plains, not to miss the vegetated lump that so impressed Upham.

Different beaches denoting different epochs follow in the villages of Norcross, Tintah, and Campbell. These tiny towns started as water stops along the railroad, which followed gravel beach ridges to avoid the rich lakebed soil, once covered by wet prairie. Settlers plowed the prairies away and installed tiling to shed excess water from some of the richest soil on earth, delivered eons ago as silt by glacial melt-rivers gushing into Lake Agassiz.

Photo by Ryan Rogers

Northeast in Rothsay stands the world’s largest prairie chicken, a delightfully kitschy roadside statue celebrating the final refuges for Minnesota’s prairie chickens. I’ve never seen a real one, and we’re too late for the birds’ sonorous spring mating ritual, but maybe we’ll rustle one up driving a series of shrinking gravel roads to the Western Prairie Scientific Natural Area. We walk into trailless grassland speckled with yellow lady’s slippers. Bobolinks, clad in tuxedo plumage, sing from plant stalks. When we tire in the heat, I sprawl with my head on a grass-covered pillow of gopher mound. A showy milkweed grows overhead, rich perfume wafting from its bloom. The flower consists of offset dials of five pronged petals, like a combination lock to a lost world, hints of which tremble in the grasses that from this low angle might reach the horizon.

After a night in Buffalo River State Park, the skies open on two days of rain. Water hasn’t fallen for a month, and the land is in need, but it complicates our agenda. Mooers suggested I trek up Frenchman’s Bluff, another state natural area and one of the highest points in northwestern Minnesota—perhaps not something to brag about, though the modest prominence does have a dreamy-sounding plant species named after it. I start up during a break in the rain. Initially, I think I’m looking at surveyor’s flags, so bright are the wood lily blooms, like stars of magma in contrast to the sky, currently the color and texture of a wet sock. The plant I’m looking for, though, is a Frenchman’s Bluff moonwort, a tiny fern found only five places worldwide. Humid air stirs as a low cloud sweeps off the Agassiz flats, snags against the hill, and dumps rain. Water is sloshing in my boots by the time I reach the camper.

In nearby Fertile, I drive by Opdahl’s Donuts and pull a U-turn. It’s an old-timey bakery where I buy a pound of cake donuts and three slices of pie, chocolate for the girls and rhubarb for me. We park in the town’s campground and are lulled to sleep by the patter of rain on the camper’s metal roof.

Photo by Ryan Rogers

Our penultimate camp lies at the end of a narrow county road crossing yesterday’s parched fields now ponded with rainwater. On a summer Saturday in Old Mill State Park, just a handful of campsites are in use, including the one next to us, occupied by a chrome-bumpered blue school bus. Steve Foldoe drove this 1979 International when it hauled kids, before buying and retrofitting it into an RV he and his wife, Naomi, named Kramer, after the television character whose presence always generated a buzz. Naomi tells me to come to the park in September, when the eponymous mill is fired up and grinds out bags of what she says is the best flour you’ll ever taste.

The rain has finally quit, so the girls and I walk to the mill. They’ve barely been out of the camper for two days and sprint about and shriek with pent-up energy. That evening and the next morning, we walk miles of trails wending along the Middle River, crossed by a stone-stanchioned suspension bridge built by the Civilian Conservation Corps. The bridge is a miniature version of the iconic span in Jay Cooke State Park, except here we have it to ourselves. The river water resembles strong tea and flows over a stony bed deposited by Agassiz waves.

Driving Highway 59 north toward our last camp in Roseau’s town park, I see something I’ve heard about but never encountered—hundreds of showy lady’s slippers blooming in the ditch. I stop on the shoulder to marvel at the ridiculously large flowers. Now is the time to savor what’s left of our trip together. In the morning, we will make one more stop before returning home.

After several millennia, 8,500 years ago, Lake Agassiz effectively dried up. Its remnants persist as the Lake of the Woods, Lake Winnipeg, Rainy, and Red lakes. Near Upper Red Lake, in Big Bog State Recreation Area, a mile-long boardwalk gives access to another Agassiz leftover. In low spots with impermeable soils, water never fully drained, and the peat moss that began growing 5,000 years ago has risen like a pillow on the land, wicking up Agassiz’s ancient water until the peat has become 20-feet-thick. Agassiz may be gone, but its legacy defines this corner of Minnesota.

The post Tracking Down Minnesota’s Lost Coast appeared first on Minnesota Monthly .