Cinnabar boat ramp is a USFS-managed access point on the Yellowstone River just south of Corwin Springs, serving as a launch site for floats through Yankee Jim Canyon.

The ramp can be well-maintained but may experience sediment washout during spring runoff conditions.

This is a critical takeout point for the McConnell to Joe Brown float and a launch point for the scenic Corwin Springs to Carbella section featuring Class II-III rapids.