Cowboy Timber Treating is a superfund site located at 91 Hwy 31, Manderson, WY 82432. The Environmental Protection Agency (EPA) identifies sites such as Cowboy Timber Treating because they pose or had once posed a potential risk to human health and/or the environment due to contamination by one or more hazardous wastes. Cowboy Timber Treating is currently registered as an Active superfund site by the EPA. However, it is not on the NPL (National Priorities List), which means the EPA does not consider it one of the nation's most hazardous waste sites.