Federal authorities hope to keep more than $20,000 in cash that a Yellowstone National Park ranger seized from two young Illinois men this summer. Prosecutors say one man admitted they had planned to use the money to buy marijuana in Oregon, then sell it in Illinois.

The money — along with some marijuana — was seized from Jacob C A Dotson and Dustin Alvis on July 8. Dotson, a 19-year-old resident of Galesburg, Illinois, and Alvis, a 20-year-old resident of Mattoon, Illinois, each admitted to misdemeanor drug possession crimes after their arrests.

The U.S. Attorney’s Office for the District of Wyoming filed a civil complaint on Wednesday, seeking the forfeiture of the cash.

Yellowstone Ranger Brad Jones stopped the men’s silver Pontiac for driving 61 mph in a 45 mph zone. Jones pulled the vehicle over at the Trout Lake Trailhead, about 14 miles west of Cooke City, Montana, and the park’s Northeast Entrance.

While talking with the men, the ranger smelled marijuana and he found a purple container with a trace of marijuana in Dotson’s pocket.

Deciding he had enough grounds to search the vehicle, Jones reportedly found a marijuana pipe, a joint, a glass jar containing 6.5 grams of marijuana, a small bottle of THC oil and a plastic container holding a small amount of marijuana, the complaint says.

Inside a backpack, Ranger Jones found two more joints, loose marijuana flakes and what turned out to be $20,337 in cash; some of the money was in the pack’s main compartment, some in an envelope with $100 bills and some wrapped in three large bundles inside a Crown Royal bag.

Dotson and Alvis were taken into custody.

At the men’s campsite at the Madison Campground, rangers later found 10.4 grams of marijuana, a small amount of LSD, 7 grams of hashish, six packages of THC concentrate/hash, five small containers of hash oil and around 10 prescription pills.

On July 11, after spending a few days in jail in Mammoth Hot Springs, both men pleaded guilty to misdemeanor counts of possession of a controlled substance. Dotson and Alvis were each ordered to pay $1,025 in fines and assessments and placed on five years of unsupervised probation; during that time, they’re banned from Yellowstone.

In interviews with ranger Jones on the side of the road and in custody, Alvis claimed he owned $10,000 of the cash, the forfeiture complaint says. Alvis reportedly said he worked odd jobs and had saved the money “all his life.” The complaint quotes Alvis as saying he didn’t use banks, generally kept his money under his mattress and took the money on the trip because he didn’t have anyone to watch it.

“When pressed for more details of his trip, Alvis asked for an attorney,” Assistant U.S. Attorney Stephanie Hambrick wrote in the complaint.

Meanwhile, Dotson reportedly told the ranger that he had so much cash because of his “expensive taste.” He initially asserted that $11,000 of the money was his — coming from his work as a shoe salesman, birthday money from his grandpa and odd jobs.

However, “Dotson eventually stated none of the money was his, but was Alvis’ money,” Hambrick alleges in the complaint. “The money was to purchase marijuana in Oregon for redistribution in Illinois.”

In the complaint, Hambrick alleges that the cash should be forfeited to the government because it was “furnished and intended to be furnished in exchange for a controlled substance,” represents “proceeds traceable to such an exchange” and/or was used or intended to be used to violate federal drug laws. If the government can prove its case by a “preponderance of the evidence” — showing it’s more likely than not that the money was being used in connection with drug trafficking — it will get to keep the money; the proceeds would generally go to the agency that made the seizure, in this case, National Park Service law enforcement.

The Illinois men will have an opportunity to dispute the government’s allegations and fight for the cash in Wyoming’s federal district court if they wish to do so.