At-Risk Reptiles in Colorado

Colorado's four reptiles of special concern on this site are spread across the state's dry edges. The long-nosed leopard lizard is found only along the far western border, in Garfield, Mesa and Montezuma counties, in sparse shrubland with plenty of bare ground. The other three live on the eastern plains: the desert massasauga, a small rattlesnake, in southeastern shortgrass and sandsage prairie, where USFWS has pointed to plowing, overgrazing and roads as threats; the Texas horned lizard, almost entirely south of the Arkansas River, on grassland with bare patches; and the ornate box turtle, Colorado's only land turtle, in prairie grassland and sandhills. CPW's 2025 State Wildlife Action Plan lists the leopard lizard, massasauga and box turtle as Tier 2 Species of Greatest Conservation Need and the horned lizard as a Species of Greatest Information Need.

In 2022, David Klute, who supervises CPW's species conservation unit, told the Parks and Wildlife Commission that the agency had done little to directly understand and conserve reptiles and that much of that work was still ahead, The Gazette reported. In 2026 the Commission rewrote Colorado's reptile and amphibian rules, noting that many of these populations are declining. The new rules took the ornate box turtle off the list of reptiles people may collect, to protect its declining populations; they also bar people from handling prairie rattlesnakes and desert massasaugas even briefly, and end wild collection of painted turtles.

What do these statuses mean? →