Elevation: 6,297 ft
This peak is not in the book.
Marks Butte is named on the USGS Grandmother Mountain quadrangle. The summit is just west of Freezeout Saddle and 1.5 miles SSE of Grandmother Mountain. When I lived in Moscow (ID), this was a popular cross-country ski destination but not a hiking destination because of the nearby roadway. Access is via FS-301 [(B)(2) on Pages 74-75 of the book]. USGS Grandmother Mountain