The Murtle River is a river in east-central British Columbia, Canada. It rises from a large unnamed glacier in the Cariboo Mountains at an elevation of 2,300 metres (7,500 ft) and flows southwest for 18 kilometres (11 mi) to the head of gigantic Murtle Lake. The river also drains Murtle Lake then flows southwest for 36 kilometres (22 mi) into the Clearwater River. The Murtle River is the longest and largest tributary to the Clearwater.
The Murtle River is known for having many waterfalls along its course. Between Murtle Lake and the Clearwater River, the Murtle drops over seven named waterfalls: McDougall, Meadow, Horseshoe, Majerus, Dawson, The Mushbowl and Helmcken Falls.
There are no records about the Murtle River being known by First Nations. The river was discovered by Joseph Hunter, a surveyor working for the future Canadian Pacific Railway, on May 25, 1874. Hunter's expedition rafted across the Clearwater River near The Horseshoe, headed east for about 13 kilometres (8 mi), and reached the Murtle River upstream from Majerus Falls. He named the river and, a few days later, Murtle Lake for his birthplace in Scotland, Milton of Murtle, near Aberdeen. Between 1872 and 1881, about 20 survey parties fanned out across British Columbia trying to find the best route for the new railway between Yellowhead Pass in the Rocky Mountains and the Pacific Coast. Three survey parties visited what is now Wells Gray Park. When the more southern Kicking Horse Pass was chosen instead in 1881, all of these meticulously examined routes across the Canadian Cordilleran, including Hunter's, were abandoned. Only three place names in the park recognize those 10 wasted years of surveys: Murtle River and Lake, Mahood River and Lake, and Marcus Falls. The latter two refer to James Adam Mahood and Marcus Smith, leaders of two other railway surveys during the 1870s.