CHAPEL HILL - The state will close a mile of nature trails and a bird-watching area at Jordan Lake because of complaints about public nudity and sexual activity.

The N.C. Wildlife Resources Commission is cutting access to the Indian Creek Wildlife Observation Area off N.C. 751 in Chatham County starting Friday.

Nudity, sexual solicitation and harassment have been a problem on the trails for years, said Isaac Harrold, manager of the State Lands Program. A recent increase has prompted the shutdown.

Last summer, uniformed commission enforcement officers issued 30 citations for public nudity alone, Harrold said. Recently, two male enforcement officers wore civilian clothes and walked the trails. Within an hour, men had solicited both officers for sexual acts.

References to Jordan Lake appear on several gay and nudist Web sites.

Harrold said the Wildlife Resources Commission doesn't have enough officers to respond to repeated problems there.

"It would essentially take full-time enforcement for a significant period of time to correct those problems. And we simply do not have those resources," he said.

The commission will block the parking lot with a cable. It will likely open the parking lot for hunters during hunting season, Harrold said.

It's up to the N.C. Department of Transportation to decide whether to post "No parking" signs along the stretch near the parking lot.

"We're hopeful that they may choose to do that," Harrold said.

The closure will mean a big change for the New Hope Audubon Society. The chapter, which has about 1,000 members across Durham, Orange and Chatham counties, has maintained a bird-watching platform at that location for 20 years.

That platform was badly damaged by wind in a 2007 storm and removed by volunteers. The society had obtained a grant and planned to rebuild it this spring. Now the society is working with the Wildlife Resources Commission and the U.S. Army Corps of Engineers to find a new site on Jordan Lake.

Thousands of bird-watchers used the old observation area over the years to observe American bald eagles fishing, flying and nesting, said Marsha Stephens, chapter president. Jordan Lake is also one of only two nesting sites in the state for the double-crested cormorant, she said.

The only commission-sanctioned trail at Indian Creek had led to the bird-watching platform, Harrold said. But nudists created another trail over time that led to the beach. Although there used to be more complaints about the unofficial trail, incidents in recent months have suggested that both trails now have problems, Harrold said.

Stephens didn't want to say much about the illegal activity that has crept into the society's bird-watching territory.

"It's an unfortunate coincidence that those two places are side by side," she said. "We definitely have two populations that are very different, that are there for two different reasons."