San Onofre State Beach, San Diego County

Parks officials this year began issuing citations to nudists at San Onofre State Beach near Oceanside, after an appellate court upheld the state's right to prohibit nudism.

That's only one indication that recreating for some beachgoers means more than sun, surf, camping and hiking.

Personal ads have been popping up on Craigslist, seeking illicit hookups in various state parks. Lt. Jeff David at Huntington State Beach said peace officers are hip to it, too; he and others have begun browsing the ads to ward off trouble.

A recent scan of Internet ads up and down the state revealed a host of offers – from a 50-year-old male seeking a sunbathing companion at Millerton Lake near Fresno to a man wanting sex in the restrooms at Lake Perris, south of Riverside.

"I have a Fantasy to have sex at a state park," wrote yet another male posting on the Inland Empire Craigslist.

But the ads show that those seeking outdoor sex are particularly intrigued by San Onofre and its partner "nude" beach, a section of Torrey Pines State Beach near La Jolla.

Ken Kramer, superintendent of the Orange Coast District, said the citations and verbal warnings to nude visitors at San Onofre came only after the "level of activities became intolerable."

Park use had soared, employees were complaining of a hostile work environment and crime was escalating, including incidents of lewd conduct, indecent exposure and sexual assault.

Kramer said the beach has had good compliance since rangers began issuing citations to the unclothed.