The search for a missing kayaker on Flathead Lake’s Polson Bay continued Monday with no sign of the missing man. 

Dr. Robert W. McDonald, a hospitalist at Providence St. Joseph Medical Center in Polson, has been missing since Saturday. 

McDonald, 43, failed to return as expected from a paddling trip on the bay. He was reported missing at about 11:15 p.m. Saturday.

That afternoon, a group that had been boating on the bay came across an unoccupied watercraft and towed it their place off Rocky Point Road. After hearing news reports about the missing kayaker, “they put two and two together and reported it then,” said Karen Sargent, a spokeswoman for the Lake County Sheriff’s Office.

She said the vessel matched the make, model and color of what McDonald was paddling, which added to confidence that an all-out search was warranted. 

Search and rescue boats, along with two helicopters, searched until about 3:30 a.m. Sunday and then resumed the search after sunrise.

“The air support we provided them pretty much ruled out any surface evidence,” said Flathead County Sheriff Chuck Curry on Monday. “So the focus of the search has turned to an underwater search at this point.”

Flathead County had a search boat fitted with a side-scan radar on the water Monday, working the shoreline area between Rocky Point Road and the Bear Harbor condominium complex where McDonald had launched.

A Lake County search boat with similar technology worked another area based on a lead that McDonald himself provided through a photograph he texted from the lake, Sargent said. 

McDonald texted the photo of the Bear Harbor condominiums at 12:30 p.m. Saturday from about a half mile to one mile from shore. He was not wearing a personal flotation device

The staff at St. Joseph Medical Center issued a statement Monday about McDonald, who started work at the hospital in late September 2013. 

“Rob is a valued member of our medical community and part of our St. Joe’s family. Please keep Rob, his family and friends in your thoughts and prayers,” said James Kiser, the hospital’s chief executive officer. “We’re all concerned about the welfare of Dr. McDonald and ask that you respect the family’s privacy at this time.”

Reporter Jim Mann may be reached at 758-4407 or by email at jmann@dailyinterlake.com.