The Oklahoma Department of Mines is monitored by the Office of Surface Mining Reclamation and Enforcement, which provides about $1 million a year to help fund the state's program.
Federal law requires mine operators to restore the mined land's topography to its general configuration before mining began.
State and federal officials have clashed over how best to do that repeatedly since 1983, according to the Aug. 5 report.
A 2010 review identified Oklahoma as the primary surface mining state with problems regulating reclamation projects.
Two of the five Oklahoma mines inspected during that review were cited for “approximate original contour” deficiencies under federal law. Another did not have a sufficiently detailed reclamation plan, the report states.
All three mines are operated by Arkansas-based Farrell-Cooper Mining Co., which is fighting the federal agency's claims in court. The state has sided with the mining company, citing federal overreach into a state regulatory enforcement agency.
The case is pending before the 10th U.S. Circuit Court of Appeals in Denver.
The Oklahoma Department of Mines said the inspector general's report ignores that the issue of “approximate original contour” has not been decided by the federal courts.