A male Gunnison sage grouse, female greater sage grouse and male greater sage grouse. The Gunnison grouse was recognized as genetically distinct from the greater grouse in 2000.

(Grace Hood/CPR News)

The fight to save the greater sage grouse will come to a head in September, when the U.S. Fish and Wildlife Service will decide whether to list the bird as endangered under the Endangered Species Act. 

Some environmental groups are lobbying for a listing because they believe it's the only way to protect the bird. Ranchers and others who have already worked to protect the grouse want to keep it off the list. 

In Colorado, a similar stand-off is building around the Gunnison sage grouse, which is currently defined as threatened, but not endangered.

The decision whether to list certain species is based on criteria set out by the Endangered Species Act.  Fish and Wildlife uses the ESA to recover marine life, plants, bugs, birds--even lichen. Each species on the list must be revaluated at least every five years by Fish and Wildlife.

Nationwide, 2,220 species of flora and fauna are listed. Colorado is home to 36 of those -- 20 animals and 16 plants --  including the Parachute beardtongue plant, the Mexican spotted owl, the black-footed ferret and the greenback cutthroat trout.

The process for listing a species involves numerous steps and takes several years. It starts with a status review in which the agency evaluates whether protection is warranted, not warranted or warranted but precluded by other priorities. If protection is deemed warranted that triggers another one-year process to publish a proposed rule, allow public comment and public hearings, and a rule is finalized.

You can download and read a full explanation of the listing process at the Fish and Wildlife website.

Theo Stein, a Fish and Wildlife spokesman, said that perhaps the most important work happens before a species is ever listed.

"There is a lot of opportunity for a lot of folks that might not normally agree on much to agree that they want to fix the problem so that we don't have a situation where there is a listing and inconvenience that comes with a listing designation."

That is the case with the greater sage grouse, where local governments, ranchers, farmers, environmental groups and others across 11 states have banded together to save the bird. In the case of the Gunnison sage grouse, conservation efforts before a listing decision weren't enough.