Exxon Mobil is brushing off criticism from Gov. Brian Schweitzer over the company's handling of the oil spill in the Yellowstone River.

The Democratic governor has cut ties between Montana and the joint Exxon Mobil-government command post, saying the energy giant is defying state open government laws by denying public access.

Exxon Mobil spokesman Alan Jeffers says the company isn't in charge of the command post, which is led by the U.S. Environmental Protection Agency. And, he says the company is trying to be transparent and has worked over the week to improve media access to cleanup areas.

Security guards working for Exxon Mobil Corp. have closely guarded access to the command post in Billings. Attempts by The Associated Press to talk to government officials there have been denied.

Schweitzer on Friday established a state-run coordination center in Billings. He also asked landowners along the river to collect samples of oil-stained water, soil and grass to use as evidence in potential claims against Exxon.