A woman will change her not guilty plea this week on a charge of hauling 290 pounds of marijuana in her recreational vehicle while in Yellowstone National Park in May, according to federal court records.

Daphne Watkins, 52, is scheduled to appear before Judge Kelly Rankin in U.S. District Court in Cheyenne on Thursday.

Court records do not indicate that her traveling partner, Janette Day, 61, has planned to change her plea.

About 10 p.m. on May 28, U.S. Park Rangers Christopher Mengak and Caitlin Schauer saw a large white Monarch SE Monaco RV at the Grant Village Marina Area with its engine off, but its lights on and its generator running, according to court records.

They suspected the RV's occupants were planning to unlawfully stay in the parking lot overnight. They parked behind the RV, and activated their car's emergency light, according to recently filed court records.

Mengak knocked on the RV's door, Watkins opened it, and Mengak first asked if they had any firearms because he'd noticed an NRA sticker on the RV's back. Watkins told him they were there because they wanted to stay at the Grant Village campground but learned it would not open until June 21.

Meanwhile, Mengak and Schauer had independently smelled burnt marijuana. Watkins admitted she had smoked some before dinner. She gave him a orange make-up pouch with two pipes and a small baggie of suspected pot.

Schauer said he had probable cause to search the RV, and Watkins then gave him a brown make-up bag with a jar with suspected pot.

Earlier court filings state Watkins told the rangers she was trafficking and had 289 pounds, but Day said the amount was closer to 200 pounds.

During a search of the RV, Schauer found large vacuum-sealed prepackaged bags weighing about 290.5 pounds.

Watkins told National Park Service agents she had been trafficking marijuana and cash between California and the east coast about four times a year for four years. She and Day have owned restaurants in Tucker County, W.Va., which is home to Kingsford Charcoal's largest charcoal manufacturing plant.

They were charged with one count of conspiracy to possess marijuana with intent to distribute, and possession with intent to distribute. If convicted, they face between five and 40 years behind bars.

They pleaded not guilty on July 31, and were ordered detained by U.S. Magistrate Judge Michael Shickich.

A few days later, Watkins' attorney Craig Silva of Casper filed a motion to suppress the seized drugs, saying the rangers did not have probable cause to search the RV. There were no "no camping" signs in the area, and there could have been any one of a number of reasons to park there.

Prosecutors responded the rangers followed procedures to check out an improperly parked vehicle, park literature and signs clearly mark designated camping areas, and smelling of marijuana smoke justified further investigation.

Prosecutors and defendants were schedule to present their cases on Aug. 21 before U.S. District Judge Scott Skavdahl, but that was canceled after Watkins announced she would change her plea.