A dendrochronological investigation of 347 seedlings and saplings from a stand of trees invading a subalpine meadow in the Wind River Mountains of western Wyoming [USA] was presented. Growth rates of these trees were found to increase as their distance from the forest edge increased. This pattern was shown to coutinue with meadow trees throughout their lives. The factors which maintain the meadows in this area primarily limit tree establishment rather than growth. Invasion began about 1890, and was most intense between 1940 and 1963. Little establishment occurred after 1963. Little establishment occurred after 1963. Examination of cattle grazing records suggests that changes in grazing pressures may be responsible for this expansion of the forest. Moderate levels of cattle utilization of the meadows appear to have resulted in abundant tree establishment by reducing competition with meadow vegetation. The lack of establishment after 1963 coincides with the cessation of grazing which occurred at about the same time.