Scott Pruitt, the head of the Environmental Protection Agency, traveled to his home state, Oklahoma, 10 times over three months this year, largely at taxpayer expense, according to a report released Monday.

The findings from the Environmental Integrity Project, a nonprofit group founded by former E.P.A. officials, are drawn from Mr. Pruitt’s calendar and the travel expenses he has submitted for reimbursement. Obtained under the Freedom of Information Act, the documents show Mr. Pruitt spent 43 out of 92 days from March through May in Oklahoma or traveling to or from the state.

The report does not assert that Mr. Pruitt’s estimated $12,000 in federally funded airfare, which includes travel to and from his home state, is improper.

Many in Oklahoma speculate that Mr. Pruitt, who was the state’s elected attorney general until assuming the E.P.A. job in February, plans to again seek statewide office. Mr. Pruitt lost a 2006 primary bid to become Oklahoma’s lieutenant governor. He was elected attorney general in 2010.