Mounties say the two were part of a tour group in canoes travelling along the Athabasca River near Edson, about a two-hour drive west of Edmonton.
RCMP say the two, along with two others, got separated from the group Wednesday afternoon.
The tour group found two of the people on the shore and airdropped them supplies, but it did not realize the other two were stranded on the river.
Mounties got the call late Wednesday, but due to darkness and the remoteness of the area, could not attempt a rescue and set out Thursday morning.
Police rescued the four and say all were examined by EMS and declined further medical attention.
Officers say those who clung to the rock told them they couldn't swim to shore due to high water levels and a strong current.
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