The Pennsylvania Game Commission failed to make sure energy companies paid what they owed in royalties from oil and gas production on state hunting lands, according to an audit released Thursday.

The commission relied on the drillers’ own data and didn’t confirm their royalty calculations were accurate or that they actually paid the money, state auditors found.

The game commission, which manages state-owned hunting lands, permits drillers to extract natural gas from the vast Marcellus Shale formation in exchange for royalties, which rose from $9.3 million in 2015 to $19.2 million in 2017. About 133,700 acres of game lands are under lease.

“Essentially, the commission is relying on gas and oil companies to say how much money they owe,” Auditor General Eugene DePasquale said in a statement.

The commission acknowledged it failed to adequately track royalties, attributing the problem to a lack of staff but said it has improved its accounting practices.

DePasquale’s audit also faulted the agency for sitting on a huge and growing pile of cash — it totaled nearly $73 million in 2018 — and failing to take those reserves into account when developing an annual budget. Auditors said the commission should consider its “full financial position” when making a budget or considering an increase in hunting license fees.