The natural cementation strength of retorted oil shale is the focus of this study. The optimum retorting temperature and residence time for development of cementation strength of minus 0.5-Inch Green River oil shale are direct mode at 1,510 deg. F and 2.0 Hours or indirect mode at 1,530 deg. F and 2.9 Hours. Correlations were developed for compressive strength as a function of curing time at 100 deg. F, for compressive strength as a function of direct mode retorting temperature and time, and for compressive strength of indirect mode retorting temperature and time. Other information developed as functions of retorting temperature, time, and mode included optimum proctor density, optimum proctor moisture content, effect of compaction water composition (tapwater versus oil shale retort water), leachate composition from the retorted shale, and permeability of compacted but uncured retorted shale. The retorted shale apparently acted as an effective filter for many of the ions in the retort water.