Lower Mash Rapid is located just downstream from Upper Mash Rapid, so there’s not a ton of time to prepare for this rapid. At the top of Lower Mash, there’s a large boulder dividing this rapid into a left and right channel. Don’t go right, unless the water is REALLY high.
There’s a large house-sized boulder on the left side of this channel, which is undercut. Past this, look out for a chute between two pointed rocks, then get ready for a very large hit. Hit this wave straight and you’ll want to have some good momentum here. Below this big hit, there is a grouping of large undercut boulders, which you’ll want to work to the right of.