Slalok Mountain, originally known as Rex's Pillar, is a mountain summit located in the Coast Mountains, in Joffre Lakes Provincial Park, in southwestern British Columbia, Canada. It is the third-highest point of the Joffre Group, which is a subset of the Lillooet Ranges. It is situated east of Pemberton, and northeast of Lillooet Lake. Its nearest higher peak is Mount Matier, to the east. Precipitation runoff from the peak drains into Joffre Creek and Twin One Creek, both tributaries of the Lillooet River. The first ascent of the mountain was made in 1963 by C. Adam, T. Anderson, and G. Richardson. The mountain's name Slalok is the traditional name for the settlement of nearby Mount Currie. The name was officially adopted on June 11, 1979, by the Geographical Names Board of Canada. The mountain and its climate supports the Matier Glacier, Stonecrop Glacier, and Tszil Glacier on the northern slopes.