Parks Canada says it is scaling back the rescue and recovery efforts for a Calgary boy believed to be drowned in the Yoho River on Friday night.

Shortly after 7:00 p.m. on July 22, two boys fell into the water near the Takakkaw Falls Day Use Area near Field, B.C.

One of the boys managed to be rescued by family members, but the other was swept away in the fast moving water.

Parks Canada, Golden Search and Rescue, the Field Fire Department, B.C. Ambulance and two helicopter crews responded and searched the area by ground and air before calling off the search at approximately 10:30 p.m. due to darkness.

Search operations continued through the weekend but have not been successful in finding the lost boy due to challenging conditions.

“The Yoho River right now is fast flowing, it's milky water, high volume , it's challenging with that and plus the terrain along the shoreline and the canyon,” said Dwight Bourdin, Resource Conservation Manager.

Parks Canada now says it will be monitoring the area as water levels change in hopes of finding him.

The incident is being handled by the Golden-Field RCMP as a missing persons case.

(With files from The Canadian Press)