The Interior Department says governors of Colorado, Montana, Nevada and Wyoming are among those who plan to join Secretary Sally Jewell and other federal officials for the announcement about greater sage grouse at the Rocky Mountain Arsenal National Wildlife Refuge outside Denver.
The government faces a Sept. 30 court-imposed deadline to decide whether it should list the chicken-sized birds as a threatened or endangered species.
Greater sage grouse range from California to the Dakotas. They've dwindled from millions to no more than 500,000 amid loss of their sagebrush habitat.
A listing could restrict oil and gas development and grazing across much of the West, though Congress has withheld funding to implement any such decision.