The Orphan Boy gold and silver mine was discovered in 1861. It is located at 10,800 feet in elevation along the Continental Divide in Mosquito Gulch, near the town of Alma in Park County (central Colorado).
The abandoned mine site is privately owned. A perennial adit discharge from a collapsed portal infiltrates through a mixture of mine waste rock and tailings before daylighting at the toe of the waste pile. The waste pile is also eroded during stormwater and snowmelt run-off events. Non-point source loading of heavy metals occurs when water interacts with the mine waste pile. The mine has been shown to have a negative effect on downstream water quality in Mosquito Creek.
Trout Unlimited initiated a Good Samaritan time critical removal action on August 19, 2024 under the direction of an On-Scene Coordinator. Work was completed in Fall 2024 before winter conditions set in. The goal of the Removal Action was to direct the adit discharge around the waste pile, regrade the waste pile and install erosion controls including capping/revegetating the waste pile.
EPA issued a letter of completion on January 14, 2025.
