Mounties say the last trace of Albert and Rita Chretien, who disappeared last month en route to Las Vegas, is a credit card purchase in Oregon state.

The Chretiens, who own a Penticton excavation business, crossed the Osoyoos-Oroville border on March 19 on the way to a trade show in Nevada.

The 59-year-old man and his 56-year-old wife never made it to the hotel.

Daughter-in-law Jennifer Chretien says the disappearance is completely out of character for the couple. "They're just not like the type to just flit off," she said. "They wouldn't make anyone worry that way."

Their cell phone and bank accounts haven't been accessed since they left home, but police say their credit card was charged once at a gas station in Baker City, Oregon.

Cpl. Dan Moskaluk said police are obtaining surveillance video from the station that could aid in the search.

"Once we establish… if it was them that used the credit card, we can then look at a more concentrated physical search of this main corridor of highways they would have perhaps utilized," Moskaluk said.

Friend and business associate Dave Goertzen says he's known the Chretiens for more than 35 years, and is anxiously waiting word of their safety.

"It's very difficult," he said. "Even contractors [with a] business relationship are finding it difficult, and some of us who know them as friends… it's hard."

The couple was travelling in a light brown 2000 Chevrolet Astro minivan with the B.C. licence plate number 212 CAV. Their family is hoping someone will remember seeing it, or the couple, and come forward.

"If someone has seen a van that looks like that, with a middle-aged couple together – if they can just give the RCMP or their local police department a call," Jennifer Chretien said.

With a report from CTV British Columbia's Brent Shearer