Companies tenured to take tours down the River of Golden Dreams are voluntarily suspending operations as of Sept. 7 to clear the way for spawning kokanee salmon.
Water levels have dropped significantly in recent weeks, and even navigating the narrow creek at the north end of the lake is challenging at this time of year.
The closure will be in effect for the next six to eight weeks.
The public is also being asked to observe the closure. If boaters wish to paddle, then they are asked to launch from the bottom of Lorimer Road after the river levels are raised by Twentyonemile Creek, or portage 600-metres along the Valley Trail from the Alta Lake Fish weir to the lower railway bridge.
The Resort Municipality of Whistler said in a release that the Tapley's section is one of the shallowest and most vulnerable parts of the river, and is an important, known spawning location for kokanee. Below the railway bridge the river is deeper, boaters come into less contact with the substrate, which has less impact on kokanee eggs incubating in the gravel.
Signs have been posted at the fish weir and at the end of Lorimer Road informing the public of the voluntary river closure.