The bright red denotes land operated by the Bureau of Land Management, Forest Service, Fish and Wildlife Service, and National Park Service in states where marijuana has been legalized. (The Washington Post)

Although the federal government hasn’t legalized marijuana, it owns millions of acres of land in places that have.

The federal government controls approximately 640 million acres of land throughout the country, much of it in the West where the four states that have legalized it — Alaska, Colorado, Oregon and Washington — are. It also operates 21.6 percent of Washington, D.C., which voted to legalize marijuana last week.

Overall, the federal government controls a combined 54.96 percent of all land in places that have legalized recreational marijuana.

That means people who possess legal amounts of marijuana in one part of the state could get into trouble if they cross into federal territory. It happened to Karen Strand in 2013 when she went hiking in Olympic National Park in Washington state. She was pulled over by a ranger for a broken taillight. He could smell marijuana in the vehicle and she was ticketed.

“It is exceptionally confusing,” she said.

In Washington, D.C., Congress gets to review the voter-approved measure legalizing pot.  Members were divided. Sen. Rand Paul (R) said he was “against the federal government telling [Washington, D.C.] they can’t,” while Rep. Andy Harris (R-Md.) told The Washington Post that he would “consider using all resources available to a member of Congress to stop this action.”

Much of the land the federal government administers is operated by the Bureau of Land Management, the Forest Service, the Fish and Wildlife Service and the National Park Service. The remaining areas are operated by the Department of Defense and other agencies, according to a 2012 Congressional Research Service study.

A January Washington Post-ABC News poll found that Americans were split on marijuana legalization. According to the poll, 49 percent of respondents said they supported it while 48 percent said they were opposed.