The Fish and Wildlife Service is reintroducing Mexican wolves in Arizona and New Mexico, part of their original range.
The Fish and Wildlife Service is expected to announce that the wolves have recovered sufficiently to be removed from the Endangered Species Act.
Another native Colorado fish population has been returned to healthy levels.
Razorbacks have been around for between 3 million and 5 million years, but trouble arrived as the population expanded in the Southwest.
The Fish and Wildlife Service said only about 4,700 Gunnison sage grouse remained in 2014.
The grizzly hunts would have been the first in U.S. outside Alaska since 1991.
Sen. Michael Bennet and Gov. John Hickenlooper asked the government to stop plans for oil and gas drilling on habitat for the greater sage grouse.
The Center for Biological Diversity, a conservation group, said Sheehan’s departure was “welcome news for America’s wildlife.”
The U.S. Fish and Wildlife Service said Thursday it will consider reclassifying the humpback chub as threatened within the next year.
Both western governors appeared together at an energy conference at Colorado State University.