Seton Lake is a lake in the Squamish-Lillooet region of southwestern British Columbia. On the northeast side is Mission Ridge. On the southwest is the Cayoosh Range. By road, the eastern end is about southwest of Lillooet. Name origin In 1827, Francis Ermatinger of the Hudson's Bay Company (HBC), the first European explorer, referred to the Seton and Anderson lakes as the first and second Peseline Lake (various spellings). In 1846, Alexander Caulfield Anderson paddled along the lakes when seeking a new HBC fur brigade route from Fort Alexandria. In 1858, Governor James Douglas commissioned Anderson to establish a route to the goldfields during the Fraser Canyon Gold Rush. The governor encouraged Anderson to name the lakes after his family. Anderson's cousin Colonel Alexander Seton of the 74th Regiment, who was in command of the of the troops on board the HMS Birkenhead, which sank in 1852, was noted for his exemplary conduct in the moment and was among those who drowned. The misspelling as "Seaton Lake" on Jorgensen's 1895 map was commonly repeated for decades in both newspaper accounts and government reports. Dimensions and tributaries The lake is long and averages wide. The surface area is . The mean depth is and maximum depth is . The lake has not completely frozen in recent centuries but has in the past. The water is a few degrees colder than Anderson Lake. The primary inflow (western end) and outflow (eastern end) are the Seton River. Clockwise, the main tributaries are Omin Brook, Carpenter Lake (via Mission Ridge tunnels), Tsee Creek, Ohin Creek, Olin Creek, Ptilla Creek, Puck Creek, Duguid Creek, Madelina Creek, and Audrey Creek, on the northern shore, and Machute Creek on the southern shore. In 1979, a creek was partially diverted to mix creek water with powerhouse water, so that sockeye salmon would not lose their bearings, but instead proceed upstream to their traditional spawning grounds. Environment The lake is bounded by snow-capped mountains that descend abruptly to the shores. Environmental conditions largely mirror the Anderson Lake geology, topography, and climate. However, glacial silt from Carpenter Lake, entering via the power station tunnel, makes the lake water much cloudier than Anderson. Ferries 1858–c.1864 Although a trail existed along the north shore, this section of the Douglas Road was mostly travelled via the lake, initially by canoe. Despite repairs and upgrades to this rudimentary trail over the years, the condition