An open-air tour vehicle jostled across the prairie at Blue Mounds State Park, as 12 riders grabbed onto hats and rails. With more than 500 acres set aside for a resident bison herd, it can take some guesswork to figure out where North America's largest land animals have wandered for the day.

"Bison can consume 26 pounds of prairie grass a day," lead naturalist Tiffany Mueller told the group. That's aided by a four-chambered stomach and nine to 10 hours of daily grazing.

She stopped a safe distance from a bull brought in from Yellowstone National Park. An estimated 30 million bison roamed the Great Plains until herds were slaughtered in the 1800s. Mueller said only 50-some bison survived back then, and all but 1% of native tallgrass prairie was carved up.

An ongoing effort seeks to bring back the bison population and keep them genetically diverse and healthy, which is why bulls might be transferred from Yellowstone to help with Minnesota's Bison Conservation Herd, a partnership between the Minnesota Zoo and the Department of Natural Resources.

Bison have roamed the state park, 3.5 hours southwest of the Twin Cities, since 1961. In early summer, cinnamon-colored calves sprint rambunctiously around the dark-brown females before pausing to nurse or nap in the lush prairie grasses.

"Our herd is a little over 100 animals," Mueller said, and the daily tours at Blue Mounds offer one of the best chances in Minnesota to see and learn about the bison, which play an essential role in restoring prairie ecosystems.

They aerate and fertilize the soil, they seem to know to graze around the wildflowers that pollinators need, and they roll onto their backs in the dirt to help shed winter coats and get relief from biting insects, leaving behind wallows that fill with rainwater used by amphibians, birds, gophers and prairie dogs.

"They really are quite special," she said of the herd. "I never get tired of seeing them."

Blue Mounds' 100-foot quartzite cliff offers expansive views of the southwestern Minnesota landscape. Wind turbines pinwheel above the prairie, silos dot farmlands, and bicyclists climb up or roll back down toward Luverne, pop. 5,000.

Six miles from the state park, Luverne offers visitors a chance to relax and enjoy a slice of nostalgia. You can borrow a bike and circle the town's 7-mile Loop Trail after dinner, cool off with a twisty cone at JJ's Tasty Drive In, or stay out late to watch a double feature at the Verne Drive-In Theater.

Birdsong and the faint clack of train cars threaded through the summer evening, the kind that begs you to roll down the car windows, wave at the cows grazing along a fence, watch a bison calf trot back to the herd, and settle in on the Blue Mounds cliff to catch a big-sky prairie sunset.

What to do around Luverne

Blue Mounds State Park offers 13 miles of hiking trails and will have an all-terrain tracked chair on hand for visitors with mobility disabilities beginning in August. The cliffs attract rock climbers, and a 1,250-foot line of ancient stones aligns with sunrise and sunset on the first day of spring and fall. Keep an eye out for nesting blue grosbeaks and prickly pear cactus blooming in late June and early July. Bison tours run Thursdays through Sundays until Labor Day, then weekends through late October (dnr.state.mn.us).

Touch the Sky Prairie, a 1,000-acre unit of the Northern Tallgrass Prairie National Wildlife Refuge, has a few trails, including one leading to a small waterfall. Meadowlarks, bobolinks and dickcissels sing from perches among the grasses and wildflowers, such as roses and four-o'clocks in early summer. Midsummer visitors can see flowers such as blazing star and rudbeckia, and big bluestem grass, which grows about an inch a day until reaching close to 7 feet (fws.gov).

Brandenburg Gallery, in a three-story former Rock County quartzite building, features lush and sweeping photographs of tallgrass prairie by Luverne native and internationally known photographer Jim Brandenburg. Brandenburg Prairie Foundation helped purchase the land and restore the Touch the Sky Prairie.

Herreid Military Museum, in the same building, ranks highly for its extensive wartime collection, with exhibits on a paratrooper priest imprisoned in a stalag, a female Marine lieutenant who helped with the Navajo Code program, and P-47 pilot Quentin Aanenson, whose story intrigued Ken Burns. Luverne was one of four communities featured in Burns' World War II documentary series "The War" (herreidmiltarymuseum.org).

Rock County History Center's location in a former Ford dealership seems perfect for displaying a rare 1909 Big Brown Luverne luxury car, one of about 30 still in existence. Luverne Automobile Co. switched to making trucks and fire trucks from 1917 into the 1970s. Meanwhile, nutcracker fans could spend hours ogling the museum's mind-boggling 5,300 variations on the Christmas classic (rockcountyhistorical.com).

Luverne added a paved 7-mile Loop Trail last year, which connects to the 6-mile Blue Mounds Trail and the 2-mile Ashby Trail. GrandStay Hotel lends bicycles free of charge, even to non-guests, for up to 24 hours. E-bikes can be rented for $10/hour at Luverne Aquatics and Fitness.

Where to eat

Sterling's Cafe and Grill serves flatbread, pasta and sandwiches on Main Street, or head near Interstate 90 where the Howling Dog Saloon offers buffalo burgers and chislic (the meat dish is a sure sign you're near South Dakota's border). Then grab a local beer or handmade ice cream sandwich on the patio at Take 16 Brewing Co.

Where to sleep

Campers can try out Blue Mounds State Park's three tipis, 18 feet in diameter and made of canvas mounted above wood platforms. There are also 14 cart-in sites and 73 drive-in campsites (52 with electric hookups) in a wooded area near a pond. Park rangers present a variety of programs most summer weekends. Campers can also check for sites at River Road, Edgehill and Luverne campgrounds. Hotels include GrandStay, Econo Lodge and a Super 8 (luvernechamber.com).

Where else to see bison in Minnesota

The Minnesota Bison Conservation Herd also has populations at the Minnesota Zoo, Minneopa State Park in Mankato, Oxbow Park and Zollman Zoo near Rochester and Dakota County's Spring Lake Park Reserve.

St. Cloud-based freelance writer and author of "Day Trips From the Twin Cities," Lisa Meyers McClintick has written for the Star Tribune since 2001.