The Mackenzie Valley Pipeline, also called the Mackenzie River Pipeline, was a proposed project to transport natural gas from the Beaufort Sea through Canada's Northwest Territories to tie into gas pipelines in northern Alberta. The project was first proposed in the early 1970s but was scrapped following an inquiry conducted by Justice Thomas Berger. The project was resurrected in 2004 with a new proposal to transport gas through the sensitive arctic tundra. Probabilistic estimates of hydrocarbons in the Mackenzie Delta and Beaufort Sea regions project that there are natural gas reserves of 1.9 trillion cubic metres (67×1012 cu ft). After many delays, the project was officially abandoned in 2017 by the main investment partners citing natural gas prices and the long regulatory process.