The Bush administration is facing two new lawsuits seeking to block last-minute changes to regulations.
A lawsuit brought by California wants to block changes to endangered species regulations that are intended to reduce input from federal scientists.
Another suit aims to keep guns out of national parks.
California Attorney General Jerry Brown announced Tuesday that he had filed the federal lawsuit claiming the Bush administration is trying to gut the Endangered Species Act.
The Interior Department issued the revised rules this month allowing federal agencies to issue permits for mining, logging and similar activities without review from biologists.
The changes also eliminate a requirement that agencies consider the effects of greenhouse gas emissions when reviewing projects on federal land.
Brown is asking the court to block the new rules.
In the second action, the Brady Campaign to Prevent Gun Violence sued the Bush administration Tuesday in hopes of stopping a policy that would allow people to carry concealed, loaded guns in most national parks and wildlife refuges.
"The Bush administration's last-minute gift to the gun lobby, allowing concealed semiautomatic weapons in national parks, jeopardizes the safety of park visitors in violation of federal law," said Paul Helmke, the group's president. "We should not be making it easier for dangerous people to carry concealed firearms in our parks."
An Interior Department spokeswoman did not comment.