MSHA Mine Data Retrieval System (as developed by PEIR ...
MSHA''s Mine Data Retrieval System (MDRS) is based on the history of each mine. Many mines have been owned by more than one operator during their histories. We are providing you with the "Operator History" for each of the mine searches you do. (See More...) Injury Rates: For an explanation of the calculation of injury rates, please use this link.