The decision by U.S. District Judge Colleen Kollar-Kotelly halts a change in regulations issued in the waning days of the Bush administration and orders further review. She set an April 20 deadline for the Interior Department to review the rule and indicate its course of action in response to the injunction.

The rule, which took effect Jan. 11, allowed visitors to carry a loaded gun into a park or wildlife refuge as long as the person had a permit for a concealed weapon and the state where the park or refuge was located allowed concealed firearms. Previously, guns in parks had been severely restricted.

The Obama administration had said it was reviewing the Bush rule but had defended it in court.

Kendra Barkoff, a spokeswoman for Interior Secretary Ken Salazar, said Thursday the department is reviewing the injunction.

The Bush administration issued the gun rule in December in response to letters from half the Senate asking officials to lift the restrictions on guns in parks that were adopted by the Reagan administration in the early 1980s.

The rule went further than a draft proposal issued a year ago and would have allowed concealed weapons even in parks located in states that prohibit the carrying of guns in state parks. Some states allow concealed weapons but also ban guns from parks.