Part of the Palouse to Cascades State Park trail. This former rail tunnel is collapsing, so a bypass route has been created around it. Not exactly a highlight as much as a warning - the bypass is steeper than expected, the gravel surface is rougher than the rest of the trail, and you should exercise caution along the entire length of the bypass. However, it beats going through a very, very sketchy tunnel filled with tumbleweeds and falling rocks. The view from the summit of the climb to the west of the tunnel is fantastic - you can see much of the trail to the east and all of the trail to the west.