CHEYENNE, Wyo. — An increasing number of visitors to Yellowstone National Park are being prosecuted for possessing small amounts of medical and recreational ***, which remains illegal on federal land.

Park rangers attribute the trend both to ignorance of federal law and the growing prevalence of legal *** in other states, including neighbouring Colorado, which has legal medical and recreational *********.

The U.S. Attorney’s Office in Cheyenne reports it prosecuted 21 ********* cases from Yellowstone in 2010 and 52 in 2013. As of Dec. 17, the office had handled 80 cases in 2014.

Those convicted of misdemeanour possession commonly receive a $1,000 fine.

The numbers are small compared to the millions who trek each year to the nation’s first national park. The bulk of the 2.2-million-acre park is in Wyoming, with slivers extending into Montana to the north and Idaho to the east.

Tim Reid, the chief ranger, said he believes the increase mirrors the prevalence of *** in society.

Alex Freeburg, a criminal defence lawyer in Jackson, Wyoming, frequently handles ********* possession cases from Yellowstone. He said his clients often are surprised when they’re charged for small amounts of *********.

“I think that it’s fair to say that it is the legalization in a couple of states. They know it’s illegal but they don’t think it’s a *****,” Freeburg said. “There’s some sort of disconnect.”

The typical ********* case arises from a traffic stop in which rangers say they smell the **** in the vehicle.

“And most people, most of the time, if a ranger says, ‘Do you have any ********* in your car?’ they’ll say yes,” Freeburg said. “In which case, there’s not a lot a criminal defence attorney can do for them.”

That happened to Gary Godina, an artist from Waipahu, Hawaii, who was cited in Yellowstone in October 2013.

Godina said rangers pulled him over for speeding in a vehicle with Colorado plates and then told him they smelled *********. He said he told them he had 3 grams of the **** that he had purchased earlier in Colorado.

“Yeah, I had to go overnight,” Godina said. “They took me up to some holding cell in Montana.”

Godina’s home state is among 23 states and Washington, D.C., that allow ********* use by people with various medical conditions. “I have glaucoma, so it’s basically a medical thing,” Godina said.

In April, he pleaded guilty and was fined $1,000.