SAN FRANCISCO — A federal judge on Friday tossed out new Bush administration rules that gave national forest managers more discretion to approve logging and other commercial projects without lengthy environmental reviews.

Utah has six national forests: Ashley, Dixie, Fishlake, Manti-LaSal, Uinta and Wasatch-Cache.

U.S. District Court Judge Phyllis Hamilton ruled that the government failed to adequately consider the effects the rules would have on the environment and neglected to properly gather public comment on the issue.

Hamilton said in her written decision that the government couldn't institute the new rules until proper environmental reviews were conducted, but she declined to specify how the nation's 155 national forests should be managed until then.

"I think people who love wildlife and care for our public forest should be elated by this decision," said Peter Frost, an attorney with the Western Environmental Law Center, one of 15 environmental groups that brought a pair of lawsuits challenging the new rules.

Hamilton issued a single ruling for both cases.

Frost said that if Hamilton upheld the new rules, "it would have likely meant the loss of species." Frost said the new rules could have made it much easier for new projects such as logging, mining, livestock grazing and road building in 192 million acres of public land.

U.S. Forest Service spokesman Joe Walsh said the government was reviewing the decision and noted it differs from rulings on similar cases in two other federal courts, including the 10th U.S. Circuit Court of Appeals in Denver.

Department of Justice spokeswoman Cynthia Magnuson said government lawyers are still reviewing the decision and have not decided whether to appeal.

When government officials announced in December 2004 the first new rules since the 1970s, they said changes would allow forest managers to respond more quickly to wildfires and other threats such as invasive species.

Forest managers have complained that without the new rules they must conduct studies that can take up to seven years to complete. The new rules would have allowed for forest plan revisions to be completed in two years to three years, officials said.