An extremely rare amphibian that exists only in captivity and within Mortenson Lake National Wildlife Refuge in the U.S. state of Wyoming. The Wyoming toad was listed as an endangered species in 1984, and listed as extinct in the wild since 1991. Before the sharp declines occurred, this toad was classified as a subspecies of the Canadian toad.

The Wyoming toad frequents floodplains and the short grass edges of ponds, creeks, and lakes. They frequently use abandoned pocket gopher and ground squirrel burrows as hibernacula.

Relatively common in the 1950s, the Wyoming toad experienced a sharp decline during the 1970s leading to an endangered species listing and it was believed the toad was extinct by 1980. The Wyoming toad was later rediscovered in the wild in 1987 along the shores of Mortenson Lake, which is an alpine lake situated at 7,256 feet (2,212 m) above sea level. The toad is historically found only in the Laramie Basin within 30 miles (48 km) of Laramie, Wyoming. By the early 1990s a captive breeding programme was begun trying to save the endangered toad from extinction, but no known wild reproduction has occurred since 1991.

Future conservation of the Wyoming toad in the wild is heavily dependent on eradicating chytrid fungus (Batrachochytrium dendrobatidis), which is probably the biggest threat to the species' survival.