A California doctor is being investigated after he landed his helicopter in Canyonlands National Park, apparently to relieve himself.

Although provisions exist for emergency landings in national parks, this particular landing may not qualify as type of "emergency" the law covers.Hikers in the northeast corner of Chessler Park, a popular backpacking/hiking area in the Needles district of Canyonlands, observed the helicopter land about 2 p.m. on Jan. 2, said district ranger Fred Patton.

Considering the landing unusual, the hikers reported the incident the next day.

"We investigated and identified a helicopter registration number that matched the description of a helicopter that flew out of the Green River airport," Patton said.

Rangers contacted the pilot, whom Patton would identify only as a "doctor from California." The pilot has since written a letter to explain why he landed in the park.

Patton would not discuss the contents of the letter, but Park Superintendent Walt Dabney said at a public hearing this week that the pilot "had to take a leak."Although the physical impact of the landing probably did not damage the land, Patton said the park is not treating the case lightly.

"It's a significant violation because of public health and safety plus the impact to wildlife," Patton said. "It's an impact on both the aesthetics and wildlife in the area."

NPS regulations classify the violation only as a "petty offense." Landing carries a $100 fine, while discharging passengers carries a $250 fine.

The incident happens at a controversial time for the Park Service and aviation industry. Citizens groups, such as the Citizens For A Heli Free Moab, are organizing politically to protest flights over the canyon country of southeastern Utah, particularly over the national parks.

Flights, however, are regulated by the Federal Aviation Administration, which only "advises" pilots not to fly below 2,000 feet above the park.

Unless Congress changes the law, the Park Service has little ability to regulate flights over the parks.

"We have no air force, we have no anti-aircraft guns and we have no authority," lamented Dabney.