Possession of marijuana is legal in Colorado, but it remains forbidden on federal land, a situation that has tripped up unaware pot enthusiasts.

Federal land surrounds the Durango area, from Mesa Verde National Park to Purgatory Resort to the Weminuche Wilderness Area.

To be clear, bringing marijuana or marijuana-laced products onto federal land in Colorado is banned, forbidden, prohibited, proscribed, verboten - don't do it.

Since legalization, rangers at Mesa Verde National Park are encountering more visitors who are in possession of marijuana, said Mesa Verde Chief Ranger Jessie Farias.

Some marijuana possessors who are caught say they were unaware of the rules, Farias said. Others admit they were willing to take the chance.

"Not knowing the law, obviously, is not an excuse," Farias said.

Small amounts of marijuana earn a ticket that totals about $125 with court fees. Amounts more than an ounce bring a more serious offense, Farias said.

Mesa Verde is considering putting a sign near the park entrance reminding visitors that pot remains illegal on federal land. Farias said Colorado National Monument in Fruita posted a no-marijuana sign, but it was stolen within a few hours.

Farias said rangers have reached out to local dispensaries to spread the word. It's more difficult to explain Colorado's legal situation to tourists.

"A lot of times, it isn't the Colorado folks," he said. "It's the folks visiting."

Mesa Verde is one of Southwest Colorado's top tourist attractions, with more than 500,000 visitors last year.

Brian Schowalter, a Durango defense attorney, said federal law enforcement has shown no leniency since Colorado voters approved Amendment 64.

"The feds, they take their power, they take their territorial jurisdiction very seriously," he said.

Schowalter cautioned against bringing edible marijuana products onto federal land. Law enforcement will weigh the entire edible, and if it exceeds an ounce, that can result in a serious charge. So a single chocolate bar that contains THC could land an unwitting user deep in the weeds.

"They'll threaten my clients with a felony," Schowalter said.

More broadly, he said, federal law enforcement continues to fight the war on drugs as if Amendment 64 never happened.

"At the frontline level, they're not conceding," he said. "They're not taking cues from society."

At Purgatory, marijuana is prohibited everywhere at the resort, said spokeswoman Kim Oyler.

Amendment 64 prohibits marijuana use in public places, including Purgatory's lodging rooms