Base line data on species cover (m /0.01 ha) and volume of space occupied (m /0.01 ha) for the initial 6 to 9 years of secondary forest succession for western larch-Douglas-fir forests is presented in tabular form for 20 study areas in western Montana. Disturbance treatments include wildfire and clearcutting followed by broadcast slash burning. Treatment conditions include both spring and fall burns (and summer wildfire) on both steep and gentle slopes. In addition, all cardnial exposures are represented over an elevational range from 4,300 to 5,300 feet (1,315 to 1,615 m). Location, physical description, predisturbance stand, and details of disturbance treatment are given for each site. Information on successional development is presented in this basic form without interpretation to provide a current, quantitative resource for modelers working on forest development and related subjects and as a source for application to other forest management problems where seral changes in vegetation constitute an important planning factor.