You also need to look at refinery utilization (how much of the capacity is being used). Reducing overall capacity will drive up utilization and may not impact total refined barrels of crude.
Trust me, refining companies aren't purposefully keeping their rates low to keep prices high. That doesn't result in higher profits unless all companies do it together, then it's a cartel (like OPEC).
Most fuel prices are regional markets. Utah/Idaho is a niche market that is only supplied by refineries in Utah, Wyoming, and Montana.