The Preliminary Assessment and Site Investigation of Tyro Mill is necessary to identify the contamination present on site in order for the Bureau of Land Management to move forward with any necessary remedial design. While some analysis of the site has been conducted in the past and various contaminants of concern have been identified on site, there is not enough relevant information to fully characterize the current site conditions. Through the development of a PA/SI report, BLM will be made aware of the contaminants that are present on site and where these contaminants are located on and around the site. The theme is open source, and you can use it for any purpose, personal or commercial.

The Tyro Mine and Mill site operated illegally for approximately 20 years and was abandoned in 1999. The mine never submitted its paperwork to BLM which caused BLM to close down the milling operation in the 1970s. Tyro Mill consisted of a cyanide mill that processed precious metal ores (primarily gold and silver).

There were also four tailing ponds that were located in the dry wash and supported by dam embankments which were also constructed of the tailings. Throughout the operation of Tyro Mill these dams and tailings piles were actively eroding. When the mill was abandoned they left approximately 70,000 cubic yards of tailings between the four dry ponds and all of the buildings were demolished.

A repository to contain the mine and mill tailings was constructed by Red J Environmental in the early 2000s to contain the leftover mine tailings on the site. The current mine tailings repository was constructed by Red J Environmental in 2004. The cover of the repository that contains the mine tailings is held in place by large boulders. Some of these boulders have been moved, allowing the mine tailings to escape from the repository.