Many birders use the trails and overlooks for great viewing opportunities of both riparian and upland bird species. Bald eagles hunt over the open waters of the river in the winter.
Great blue heron rookeries exist adjacent to the park. Migratory and resident birds in the parks include several species of raptors, waterfowl, shorebirds and grassland species, such as lark and vesper sparrows, horned lark and western meadowlark.
Visitors might observe any of these species: Red-tailed hawk, bald and golden eagles, osprey, varieties of swallows and hummingbirds, black-crowned night heron, ring-necked pheasant, quail and wild turkey. Wildlife is abundant along the riparian corridors.
See the James M Robb Bird Checklist.
Because of the spatial distribution and size of the parks, large mammal habitat is somewhat limited. Mule deer and mountain lion are occasionally sighted. While cottontail rabbits, coyote, red and gray fox, raccoon, beaver, muskrat, prairie dog and ground squirrel are frequently observed.
Ponds and backwaters with emergent vegetation provide habitat for many amphibians, such as leopard frog, lizards and snakes.
Anglers enjoy the warm-and cold-water fishing opportunities, which include channel catfish, bluegill, largemouth bass, black bullhead, a sunfish/bluegill hybrid, carp, rainbow and cutthroat trout.
Wetlands within the park also provide the backwater habitats needed for various life cycles of endangered and threatened fish species, such as humpback chub, bonytail, Colorado pikeminnow and razorback sucker.