MountainWest Overthrust Pipeline, a small 261-mile pipeline extending from Whitney Canyon, Wyoming, to Wamsutter, Wyoming, is owned by MountainWest Pipelines Holding (The Williams Companies) and operated by MountainWest Overthrust Pipeline, LLC. Operating at more than 50% utilization, it primarily serves midstream and marketer sectors, with key clients including Citadel Energy Marketing, LLC, Hartree Partners LP, and Rockies Express Pipeline.