Frequent (4--12 times per year) measurements of six 3-line (lengths 10--40 km) strain networks located along the locked sections of the San Andreas fault in southern and central California provide a time history of deformation along the fault in the interval 1982--1986. The standard error in measurement ranges from 0.4 ppm in line length for the shortest lines to 0.2 ppm for the longest lines. Except for one example of coseismic offset and postseismic relaxation the observations are at least marginally consistent with uniform-in-time deformation. The records of deformation at the networks closest to the epicenters of two recent magnitude 6 California earthquakes (1984 Morgan Hill and 1986 North Palm Springs) were particularly stable in the year preceding the earthquakes. Thus it is unlikely that these earthquakes were triggered by regional strain events. However, marginally significant anomalies were observed 12--18 months before both earthquakes. ¿American Geophysical Union 1987