Jim Brandenburg / Thickspike Gayfeather (Liatris pycnostachya) flowering on tallgrass prairie, Crow-Hassan Park Reserve, Minnesota

Jim Brandenburg / Thickspike Gayfeather (Liatris pycnostachya) flowers with eagle-shaped cloud, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / American Bison (Bison bison) herd of adults and calves on tallgrass prairie, South Dakota

Jim Brandenburg / Monarch (Danaus plexippus) butterfly group resting on Thickspike Gayfeather (Liatris pycnostachya) flowers, North America

Jim Brandenburg / American Bison (Bison bison) male walking through tallgrass prairie, South Dakota

Jim Brandenburg / Burrowing Owl (Athene cunicularia) trio peeking out of burrow in tallgrass prairie, South Dakota

Jim Brandenburg / Cloudy sky over tallgrass prairie, Wind Cave National Park, South Dakota

Jim Brandenburg / Prairie burn in Tallgrass Prairie National Preserve, Oklahoma

Jim Brandenburg / Thickspike Gayfeather (Liatris pycnostachya) flowers in grass, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Tree in tallgrass prairie, Blue Mounds State Park, Minnesota

Jim Brandenburg / Storm over Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

LYNN M. STONE / Bottle Gentian (Gentiana andrewsii) flowering in tallgrass prairie remnant, Downers Grove, Illinois, USA

LYNN M. STONE / Monarch Butterfly (Danaus plexippus), showing some wear and tear on wing, feeding on nectar of Rough Blazing-Star (Liatris aspera) growing in tallgrass prairie remnant, Downers Grove, Illinois, USA

LYNN M. STONE / Eastern Tiger Swallowtail butterfly (Papilio glaucus), dark phase female, on Pink Thistle in tallgrass prairie remnant, Illinois, USA (an intermediate phase between the typical yellow and the entirely...

Jim Brandenburg / Sioux Quartzite in tallgrass prairie with oncoming storm, Blue Mounds State Park, Minnesota

Jim Brandenburg / Great Plains Toad (Bufo cognatus) male calling and competing for access to female in amplexus with another male, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, southwest Minnesota

Thomas Lazar / Eastern bluebird (Sialia sialis) male in breeding plumage perched, Tallgrass Prairie WR, Wisconsin, USA, June

Thomas Lazar / Eastern bluebird (Sialia sialis) male in breeding plumage perched on nestbox sumac tree, Tallgrass Prairie WR, Wisconsin, USA, May

Thomas Lazar / Eastern bluebird (Sialia sialis) male in breeding plumage perched on nestbox, Tallgrass Prairie WR, Wisconsin, USA, June.

Thomas Lazar / Eastern bluebird (Sialia sialis) female in breeding plumage perched on nestbox with insect prey for chicks, Tallgrass Prairie WR, Wisconsin, USA, June

Thomas Lazar / Eastern bluebird (Sialia sialis) female in breeding plumage perched on nestbox with insect prey for chicks, Tallgrass Prairie WR, Wisconsin, USA, June

Thomas Lazar / Eastern bluebird (Sialia sialis) female in breeding plumage, Tallgrass Prairie WR, Wisconsin, USA, May

Thomas Lazar / Eastern bluebird (Sialia sialis) pair in breeding plumage perched on nest box, female above, Tallgrass Prairie WR, Wisconsin, USA, May

Thomas Lazar / Eastern bluebird (Sialia sialis) male in breeding plumage, Tallgrass Prairie WR, Wisconsin, USA, May

Thomas Lazar / American goldfinch (Carduelis tristis) male in breeding plumage, Tallgrass Priarie WR, Wisconsin, USA, June

Jim Brandenburg / Sioux Quartzite on tallgrass prairie, Blue Mounds State Park, Minnesota

Jim Brandenburg / Sioux Quartzite, Blue Mounds State Park, Minnesota

Jim Brandenburg / Tallgrass prairie, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Tallgrass prairie, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / American Bison (Bison bison) herd in winter, Blue Mounds State Park, Minnesota

Tim Fitzharris / Tallgrass prairie showing grasses and bushes, Tallgrass Prairie National Preserve, Kansas

Tim Fitzharris / Tallgrass Prairie National Preserve, Kansas

Michael Durham / Columbia Sharp-tailed Grouse (Tympanuchus phasianellus columbianus) erupting into flight from tallgrass, Zumwalt Prairie Preserve, northeast Oregon

Jim Brandenburg / Monarch (Danaus plexippus) butterfly on Thickspike Gayfeather (Liatris pycnostachya) flowers in tallgrass prairie, Minnesota

Jim Brandenburg / Short-eared Owl (Asio flammeus) with cocked head, Tallgrass Prairie National Preserve, South Dakota

Jim Brandenburg / Tallgrass prairie under stormy skies, South Dakota

Tim Fitzharris / Oak (Quercus sp) trees shrouded in fog, tallgrass prairie in Flint Hills which has been taken over by invasive Great Brome Grass (Bromus diandrus), Kansas

Tim Fitzharris / Misty morning over prairie, Tallgrass Prairie National Preserve, Kansas

Claus Meyer / Tall grasses and marshes of Taim area, seasonally flooded plains with diverse wildlife, Rio Grande Do Sul, southern Brazil

Jim Brandenburg / Big Bluestem (Andropogon gerardii) grass blowing in the wind, an important part of the tallgrass prairie ecosystem, South Dakota

Jim Brandenburg / Monarch (Danaus plexippus) butterfly on Thickspike Gayfeather (Liatris pycnostachya) flower in tallgrass prairie, Minnesota

Jim Brandenburg / American Bison (Bison bison) herd of adults and calves on tallgrass prairie, South Dakota

Jim Brandenburg / Common Reed (Phragmites australis) field at sunset, Tallgrass Prairie, South Dakota

Jim Brandenburg / Pronghorn Antelope (Antilocapra americana) resting in grass, South Dakota

Jim Brandenburg / Prairie burn in Tallgrass Prairie National Preserve, Oklahoma

Jim Brandenburg / Prairie and storm clouds, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Abstract coneflowers on tallgrass prairie, North America

Jim Brandenburg / Sign and storm clouds, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Thickspike Gayfeather (Liatris pycnostachya) flowers in grass, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Sioux Quartzite in tallgrass prairie with oncoming storm, Blue Mounds State Park, Minnesota

Jim Brandenburg / Sioux Quartzite in tallgrass prairie, Blue Mounds State Park, Minnesota

Jim Brandenburg / Sioux Quartzite on tallgrass prairie, Blue Mounds State Park, Minnesota

Jim Brandenburg / Sioux Quartzite on tallgrass prairie, Blue Mounds State Park, Minnesota

Jim Brandenburg / Violet Wood Sorrel (Oxalis violacea), tallgrass prairie, Minnesota.

Jim Brandenburg / Sioux Quartzite scratching post rubbed smooth by American Bison (Bison bison) over a period of hundreds of year, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Sioux Quartzite scratching post rubbed smooth by American Bison (Bison bison) over a period of hundreds of year, Touch the Sky Northern Tallgrass Prairie National Wildlife Refuge, Minnesota

Jim Brandenburg / Stormy skies over tallgrass prairie, Wind Cave National Park, South Dakota

Jim Brandenburg / American Bison (Bison bison) herd of adults and calves on tallgrass prairie, South Dakota

Jim Brandenburg / American Bison (Bison bison) herd of adults and calves on tallgrass prairie, South Dakota

Jim Brandenburg / American Bison (Bison bison) calf in tallgrass prairie, South Dakota

Jim Brandenburg / Touch the Sky Prairie at sunrise, Northern Tallgrass Prairie National Wildlife Refuge, Minnesota