A large volume of pumice is widely distributed over the Klamath Indian Reservation in 'flow' and 'fall' deposits. The flow material on the Reservation is restricted to the area west of Klamath Marsh, and the fall material is thickest immediately southeast of the Marsh.
Tests of the chemical and physical properties of the pumice indicate that the pumice is suitable, with some limitations, for use as an aggregate and as a low-grade abrasive. Preliminary examination also indicates that with proper processing it may have a potential use as pozzuolana. The pumice is similar to material now being marketed for lightweight aggregate in Oregon, but processing of the pumice is necessary to obtain a suitable size distribution of the particles.