Wyoming has more than 2,000 species of ferns, conifers, and flowering plants. The eastern third of the state is dominated by prairie grasses while desert shrubs, primarily sagebrush, cover the Great Basin in the west. Rocky Mountain forests consist largely of pine, spruce, and fir. In 2003, only one plant species was endangered, blowout penstemon. Three species were listed as threatened by the US Fish and Wildlife Service. They included Colorado butterfly plant, Ute ladies'-tresses, and desert yellowhead.

The most common game animal found in Wyoming is the mule deer. Others include the white-tailed deer, pronghorn antelope, elk, and moose. The jackrabbit, antelope, and raccoon are plentiful. Wild turkey, bobwhite quail, and several grouse species are leading game birds. More than 50 species of non-game birds also inhabit Wyoming all year long. In 2003, 13 Wyoming animal species were listed as threatened or endangered, including the black-footed ferret, grizzly bear, whooping crane, razorback sucker, Kendall Warm Springs dace, and Wyoming toad.