Rattlesnake Hill - Looking Over the Old Arsenal

A stop on Rocky Mountain Arsenal Wildlife Loop, a free self-guided tour.

A short trail climbs to this overlook, one of the few high points on the refuge. From here you can see how much of the old Arsenal has returned to grass, and the Front Range lines the western horizon on clear days. The bison corral below is where the herd gets its yearly health checks.

The prairie around you also holds the cleanup's hardest work. During World War II the Army made mustard agent, lewisite and incendiary munitions here, and in the 1950s it produced the nerve agent sarin. A pesticide plant, run by Shell from 1952 to 1982, made chemicals such as aldrin and dieldrin. Wastes went into open basins, and about 2 km north of this hill lay Basin F, whose asphalt liner failed.

The cleanup, finished in 2010, buried contaminated soil in two hazardous waste landfills and under thick covers, and groundwater is still pumped and treated. The Army keeps about 1,000 acres closed to the public to maintain them.

Getting here: At mile marker 8, turn south on the Wildlife Drive and follow it to the Rattlesnake Hill parking area, then walk the short trail to the overlook.

Did you know?: The Army and Shell spent about $2.1 billion on the cleanup, one of the largest Superfund efforts in the country.

Photo op: From the top of the overlook, shoot west so the restored prairie leads the eye toward the mountains.

More on Wikipedia: Rocky Mountain Arsenal · Sarin · Dieldrin · Superfund

Rattlesnake Hill - Looking Over the Old Arsenal

Stops on this tour