The second largest “fin” formation on the east side of the canyon above the river, Spare Rib Buttress has some of the best climbing in the canyon as well as one of the best climbs in the entire state of Montana. Most routes here are along the exposed prow, with the two cracks splitting the face being the most popular.Approach from the 35 MPH bridge and follow the trail under the bridge to a nice single track trail alongside the river. Link up with the Blackline-Sparerib trail to begin up the steep switchbacks to the Skyline Buttress. You will pass Blackline Buttress and Ashes of Stone Crag one your hike up before reaching the Skyline formation. From Skyline continue north along the main trail to reach the base of Spare Rib.