Search and rescue crews are combing a mountainous area near Revelstoke, B.C. for signs of a pilot and his girlfriend who failed to return to Edmonton Saturday.

The couple identified as Dominic Neron and Ashley Bourgeault took off from Penticton on Saturday afternoon. They were expected to land in the Alberta capital around 6:40 p.m. local time, and were reported missing when their plane was four hours overdue.

Neron's cellphone was picked up by a tower about 32 kilometres northeast of Revelstoke Saturday night, so crews focused their efforts on that area and up into Rogers Pass.

Officials said the pilot did not issue a mayday call during the flight, and the Joint Rescue Co-Ordination Centre said no flight plan was filed.

But searchers were unable to locate the aircraft, and returned Sunday and Monday to search the path their plane likely took.

Efforts were hampered by a low cloud ceiling, but visibility improved Monday and crews were hopeful they'd be able to see the area more clearly.

The pilot who sold Neron the single-engine plane earlier this year described the search area as rugged and forested.

"The valleys are very close in… It's very rough terrain," Eldon Gjesdal told CTV Edmonton.

"We're just hoping and praying that he found a safe place to land."

With reports from CTV Edmonton's Shanelle Kaul and CTV Vancouver's David Molko