The Mackenzie Mountains EarthScope Project—a collaboration between Colorado State University, the University of Alaska, Michigan State University, and Yukon College—deployed a roughly linear, 40‐station broadband seismographic network. This network crossed the actively deforming Northern Canadian Cordillera and the Mackenzie Mountains in Yukon, Canada; it also extended into the Canadian Shield in Northwest Territories, Canada. The array was deployed between July 2016 and August 2018 (with four pilot stations installed in July 2015 and three extended stations operating through August 2019) coinciding with and complementing the deployment of the EarthScope Transportable Array to Alaska and western Canada. In this article, we present an overview of project scientific objectives, station configurations, and site conditions; discuss environmental challenges, including those that resulted in station downtime (e.g., spring flooding and encounters with bears); and suggest potential solutions to such subarctic challenges for the benefit of future deployments in comparable regions. We also include an initial characterization of seasonal and geographic variations in ambient seismic noise for the northwestern Canadian Cordillera.