Parks Canada is scaling back its recovery operation for a hiker who fell over a 100-metre waterfall in Yoho National Park over the weekend.

The missing hiker, a 19-year-old man from Calgary, is believed to have died after falling into Twin Falls on Sunday afternoon while hiking in a group of four at the towering and picturesque site in British Columbia, just west of the Alberta border.

Rescuers scoured the area until nightfall on Sunday and then resumed "at first light" on Monday, said Parks Canada spokesperson Tania Peters, but they have still found no sign of the young man.

After concluding an extensive search of the area from the air and on the ground, with this assistance of trained dogs, Parks Canada announced Wednesday the recovery effort would be scaled back but officials would continue to monitor the area.

"The thoughts of all Parks Canada personnel are with the young man's family and friends," the federal agency said in a release.

This incident is still considered a missing person case and is now being handled by the Golden RCMP.