The narrow-headed garter snake is a nonpoisonous snake found in and near the cool, clear headwater streams of the Southwest. With its stripeless, grayish-colored body, it has been called “drab” in color — but its irregular dark spots, small body and long, triangular head make it unique. Like water snakes, narrow-headed garter snakes are highly aquatic and feed on fish in strong river currents, with their namesake elongated heads reducing drag during underwater strikes.

The appearance and aquatic habits of the narrow-headed garter snake are unlike that of any other garter snake you might encounter. But the odds of encountering one aren't good: Unlike the garter snakes that frequent backyard gardens across the country, narrow-headed garters are quite rare. Scientists have been unable to locate these snakes in most of the places where they once thrived. Remaining populations are small and isolated.

The main causes of their population declines are habitat alteration and the introduction of nonnative predators — including fish, crayfish and bullfrogs. In fact, these threats are leading to the decline of nearly the entire native aquatic fauna of the Southwest. The Center did a status report on this snake in December 2011.