Pemberton Pass, , also formerly known as Mosquito Pass, is the lowest point on the divide between the Lillooet and Fraser River drainages, located at Birken, British Columbia, Canada, in the principal valley connecting and between Pemberton and Lillooet. The pass is a steep-sided but flat-bottomed valley (or "thalweg") adjacent to Mount Birkenhead and forming a divide between Poole Creek, a tributary of the Birkenhead River, which joins the Lillooet at Lillooet Lake, and the Gates River which flows northeast from Gates Lake (also known as Birken Lake), at the summit of the pass (also known historically as Summit Lake or Gates Lake), which flows to the Fraser via Anderson and Seton Lakes and the Seton River.