The protection of subterranean roosts deemed critical for the long-term conservation of bats has become increasingly common throughout the United States. In the western U.S. the majority of bat gates have been installed to protect abandoned mine openings during Abandoned Mine Reclamation activities (AML). Variation in local geology, portal stability, access, scope, and reclamation budgets has resulted in a range of gate styles, materials, and installation methods. While the unifying objective of gate installation is the long-term conservation of bats and concurrent elimination of human access to dangerous abandoned mines, there has been a paucity of post-gating monitoring to determine the long-term effectiveness of bat gates in general, and of different gate types and materials more specifically. As a result, inference of bat gate effectiveness is largely anecdotal. Typically attempts to measure gate "success" are based on casual observations, collected from a small geographic area and over limited period of time. While these observations provide a platform from which research on gate success can be developed, the observations themselves are not data and should be treated accordingly. This presentation includes data collected throughout the western United States in years preceding treatment, during treatment, and in the years following treatment at several large-scale AML projects. The goal of this study was to understand the overall effectiveness of AML mitigation programs for maintaining use of abandoned mines by bats, facilitating standardization of best management practices for maintaining bat populations in historically mined landscapes.