THE DISCOVERY of a mile-long illegal mountain bike trail in Forest Park last week created an uproar and threatened a years-long process to build new, legal bike trails in the sprawling park.

Though plans to open up more trails in Forest Park to mountain biking will roll forward, the controversy makes clear Portland Parks and Recreation's inability to exert control over Forest Park.

At 5,156 acres, Forest Park is 50 percent of all of Portland's parkland—but employs only one full-time, year-round park ranger.

Without enough watchful eyes, one or more mountain bikers managed to carve out a mile-long path, move boulders to build a small dam, cut down live trees, and build a series of jumps in an ecologically sensitive part of the park.

"It is not only illegal, it is tragic," said Parks Director Zari Santner at a tense meeting last week of the citizen Forest Park Singletrack Cycling Committee, which is tasked with recommending how to open up 20-30 new miles of Forest Park trails to bikes. "The reason we convened this committee is because we were fearful of something like this happening."

Police are investigating who built the trail, which the parks department estimates as causing $80,000 in damage.

Currently, only 30 miles of Forest Park's 70 miles are open to bikes and only one-third of a mile are the narrow "singletrack" paths mountain bikers prefer. "We need to figure out how to make facilities that are more attractive to bikes, so people don't ride on trails that are illegal," says Tom Archer, who sits on the city's committee and also directs mountain biking group Northwest Trail Alliance. Archer condemned the illegal trail harshly in a letter to members last week.

The trail raised serious concern for environmental experts because its builders hacked through the north section of Forest Park, where there are few invasive species and many wild animals. "If you were to go out there and look, you'd see fresh elk scat and hair," says Parks Natural Areas Manager Astrid Dragoy.

BikePortland.org Editor Jonathan Maus headed out to the illicit trail last week and agreed that the damage was substantial.

"It looked like someone came in with a weed whacker," says Maus. But despite the impact, Maus thinks the debate over the trail has been overblown. "It's easy to understand why people are getting hysterical about this, but it's an isolated, illegal act," says Maus. "The park is suffering from lack of enforcement in general—not just in relation to mountain bikers."

Committee member Frank Selker made a similar observation at the meeting last week, noting, "The biggest threats to the park are invasive species and lack of funding."