DENVER -- The U.S. Forest Service said it has denied a request by the Rainbow Family for a permit to gather in the Routt National Forest this summer.

Members of the group applied for a permit yesterday -- more than a week after they started showing up in the forest. Officials said at least 500 people had already arrived. The Forest Service said groups of 75 or more people need a permit to gather in a national forest.

The Rainbow Family's annual event usually draws 15,000 to 20,000 people to public lands -- at different sites each year.

Forest Service officials said the group's permit application didn't meet the required guidelines. Officials first attempted working with members of the Rainbow Family in September 2005 for this year's gathering.

"The group showed up without any coordination with the Forest Service, even after numerous attempts," Forest Supervisor Mary Peterson said. "Events of this magnitude require planning and careful consideration of public safety and natural-resource protection. No one is exempt."

The agency said the site proposed for the gathering is served by only one road -- not enough to get large numbers of people out in case of a fire at a time when fire danger is high.

Officials also said the proposed gathering conflicts with other events and groups that already have permits for the same area at the same time.