The Alexander MacKenzie Heritage Trail (also Nuxalk-Carrier Route or Blackwater Trail) is a 420 km (260 mi) long historical overland route between Quesnel and Bella Coola, British Columbia, Canada. Of the many grease trails connecting the Coast with the Interior, it is the most notable and often is referred to as the Grease Trail.
The trail was originally used by the Nuxalk and Carrier people for communication, transport and trade, in particular, trade in Eulachon grease from the Pacific coast.
During his trek from Montreal to the Pacific Ocean in the late 18th century, Alexander MacKenzie was led by Nuxalk-Carrier guides, when natural obstacles in the Fraser River prevented his continued water route.
Mackenzie's group "took the Parsnip River, crossed the continental divide, and eventually canoed down the Fraser River to Alexandria just south of Quesnel. On the advice of local First Nations people, who guided Mackenzie and his party to the Pacific Ocean, they gave up the river route for an overland one. The overland journey started just above the mouth of the Blackwater River at the West Road River west of Quesnel, taking them through the Upper Blackwater, along the Eliguk Lake and Gatcho Lake, through parts of what is now Tweedsmuir Provincial Park, over the Rainbow Mountains, into the Bella Coola Valley and "Friendly Village". The local people took the group down the Bella Coola River, over the salt water into the Dean Channel." He reached the ocean on July 20, 1793, completing the first recorded transcontinental crossing north of Mexico. The route was designated as an official heritage trail by the Heritage Conservation Act in 1987.