The northern prairie stirs to life early. Even before the sun lines the horizon in red, birds trill and chirp.

I am at the edge of a vast grassland in west-central Minnesota, waiting for a sign of spring's long-awaited return.

Last fall's green carpet has turned brown. Winter's snow has melted, enveloping seeds in reviving moisture. This is the Bluestem Prairie Preserve in May, and I am sitting in a bird blind created by the Nature Conservancy. I had arrived in the dark, walked 10 minutes in fading starlight and the distant glow of Fargo, opened the windows of this simple wooden structure, settled onto a narrow padded bench and hoped the greater prairie chickens would come.

Like all the joys of springtime, this outing requires patience.

At first, I see little more than my own breath. The temperature hovers in the mid-30s. A duck floats on a glassy pond, occasionally diving down for breakfast. A red-winged blackbird perches on reeds. A Canada goose honks overhead. Hopeful songs of bobolinks and meadowlarks build slowly. Then a loud, sustained, baritone rumble joins the cacophony.

The prairie chickens begin their springtime dance.

Outside the window, a few of the white-and-brown striped grouse appear on a patch of short dried grasses under an indigo sky. Nearly a dozen others follow quickly, flying from their nests in tall grasses to their own small territories in the open field, strutting and cackling and making a show. The sudden convergence reminds me of teens descending on a shopping mall on a Friday night — and the purpose might not be too divergent.

For the male prairie chickens, it's all about wooing a female.

To hold their ground and try to expand it, males face off at territorial lines, fly over one another's backs, claw in midair. They stutter-step in a kind of prairie tap dance. When a female approaches, they hoot and bound into the air to get noticed.

Amid the spectacle, a moaning coo resounds across the prairie and amplifies in the confines of my small blind. It's called booming, a trademark of the courtship display. The sound is made when males raise their neck feathers and blow air into a pair of orange neck sacks until they become as round as balloons.

The flamboyant glowing orbs make a good stand-in for the sun, until the real thing, too, lights up the prairie and begins to warm the day.

"It's nice in spring when the sun angle really gets up there," said Brian Winter, program director for the Nature Conservancy. He has lived on this native prairie for nearly 30 years. The heat of the sun is only one sign that the seasons are shifting. "When I step out my front door early in the morning and I can hear these prairie chickens booming, to hear that call, I know it's spring."

Another sign of spring 100 miles east: a hushed but insistent chirping coming from a crook in a tree. Dusk was approaching in Itasca State Park as I hiked along the park's namesake lake. The sound stopped me in my tracks. I peered at the tree to see what bird might be calling, but then realized I was picking up instead the murmur of a tree frog.

In the stillness, other sounds grew more pronounced. The rat-a-tat-tat of a woodpecker boring down on bark to release a juicy insect. The buzz of a chickadee's wings in flight. The chatter of young boys fishing off a dock.

Just part of the thrum of the northern forest in springtime.

I craned my neck for a better angle, hoping to spy the tiny frog, which can climb trees and change color to camouflage itself. I saw nothing.

Luck had been with me earlier. I had rented a bike to pedal around Itasca State Park's Wilderness Drive. When I hopped off to get a closer look at a cluster of yellow lady's slippers, their cupped petals veined with purple, a rustle in the dried leaves caught my attention. A frog with speckled brown skin paused before it bounded into the underbrush.

Though the thermometer approached 80, the ground held firmly to spring. Ponds swelled. Wet paths turned shoes soggy. On my hikes that day, I often heard frogs plopping into water.

Louder splashing came from the park's famous Mississippi River headwaters. Visitors often attempt to walk across the low-lying dam of rocks built to mark the river's beginning. In spring, though — especially this spring — the rocks are mostly submerged and wet with the spill that will flow 2,552 miles before it enters the Gulf of Mexico.

"Some people have tried to walk across," a park ranger told me. "But so far this year, I haven't seen anybody make it without getting wet."

I took off my shoes and socks and dipped in my toes, but nothing more. The lake held the chill of the ice cover that melted not many weeks ago.

• • •

The next morning, I walked over water.

At the Big Bog State Recreation Area, just 40 miles south of the Canadian border in Waskish, I strolled a milelong aluminum and plastic boardwalk that stretches over this wet and wild world.

All around, small purple blooms of the bog laurel carpeted the floor in a brilliant show of spring. The white wispy flowers of cotton grass swayed in the breeze. Tamaracks, those coniferous trees that sprout fresh needles each spring, were lined in lime green, the color of new growth.

The ground looked firm, but that was deceiving. Streams of water flowing below the surface keep it soft and spongy, explained Doug Easthouse, the state park manager for the Big Bog. Such strangely wonderful plants as carnivorous sundew and pitcher plants thrive in this acidic environment, built on many feet of mushy peat. Except for signs of wildlife — the thin watery pathway forged by a river otter, the sunken footprints of moose — the landscape stretches as far as the eye can see. The 500-square-mile bog is the most intact and undisturbed ecosystem in Minnesota.

Tens of thousands of years ago, the area drowned under monstrous Lake Agassiz, which was formed when glaciers flattened the land and then melted. The waters stretched over what is now northern Minnesota, Manitoba, Ontario and Saskatchewan.

Settlers hunting for land at the turn of the past century hoped ditches would drain away the moisture so they could farm the rich soil. They gave up, waterlogged and poor.

It is still a watery world.

On the day I visited, a mizzle of rain fell as Easthouse and I clanked our way to the tip of the boardwalk. "It was a long wait up here for spring this year," he said. "People want to know when to come and see the flowers. I tell them now, quick."

We wait and wait for the beauties of spring to arrive, but in a day, tender blooms can shrivel and burn.

Driving home in the rain, summer seemed far off. I headed south, past the greening forests of Itasca again, and the blossoming prairies off to the west. Then, just south of Grand Rapids, I turned off the wipers. The sun — with the power to warm the earth, fuel spring's renewal, coax buds into leaves — peeped out from behind a cloud.

Kerri Westenberg • 612-673-4282 • kwestenberg • Brian Peterson • 612-673-4783 •