This story is a staff report from The Paper.

The U.S. Fish and Wildlife Service published a final rule in the Federal Register this week designating 23,785 acres of critical habitat for the narrow-headed garter snake in five Arizona counties and three New Mexico counties (Grant, Catron and Hidalgo counties). The majority of the land in the critical habitat is federal, however about a quarter of it is privately owned. The Glenwood State Fish Hatchery is also included in the critical habitat.

The notice states that the “narrow-headed garter snakes are primarily found in rocky stretches of canyon-bound headwater streams that have perennial flow or limited spatially intermittent flow that is primarily perennial.” The snake primarily lives in the water.

The narrow-headed garter snake has been on a list of threatened species since 2014. In the last 50 years, the total population has declined significantly.

The waterways now protected for the snake under the Endangered Species Act include 46 miles of the Gila River, 71 miles of the San Francisco River, 52 miles of the Blue River, 20 miles of the Tularosa River and 27 miles of the Verde River.

“Protecting these rivers will make a real difference for the narrow-headed garter snake,” said Brian Segee, endangered species legal director at the Center for Biological Diversity. “The only way to save these river-dwelling snakes is to shield the places they live.”