Annual surveys of trilateration and leveling networks in and around Long Valley caldera in the 1982-1985 interval indicate that the principal sources of deformation are inflation of a magma chamber beneath the resurgent dome and right-lateral strike slip on a vertical fault in the south moat of the caldera. The rate of inflation of the magna chamber seems to have been roughly constant (0.02 km3/yr) in the 1982-1985 interval, but the slip rate on the south moat fault has decreased substantially. In addition, there is evidence for a shallow source of dilation (possibly dike intrusion) beneath the south moat of the caldera in 1983 and less certain evidence for a deep source (possibly magma chamber inflation beneath Mammoth Mountain) in the western caldera in 1983-1985. Deformation in the 1985--1986 interval as inferred from the trilateration alone seems to be similar to that observed in 1984--1985.