Deformation across the Fairweather and Totschunda faults is estimated from repeated surveys of geodetic networks that span those faults. Surveys in 1967, 1983, and 1986 of networks crossing the Fairweather fault indicate that right-lateral engineering shear strain is accumulating across the 1958 earthquake rupture at a rate of 1.6¿0.2 μrad/yr. This rate of deformation is one of the highest observed across a strike-slip fault system, and it is several times greater than the secular rate of deformation across locked parts of the San Andreas fault. The rate of strain accumulation across the Fairweather fault was the same in the two intervals 1967--1983 and 1983--1986 and is thus believed to be a secular rate rather than a transient associated with the 1958 earthquake. The 1983--1986 line length changes are best fit by a model fault that is locked from the surface to a depth of 7 to 9 km and is slipping in a right-lateral sense at a rate of 41 to 51 mm/yr below that depth. Models with the fault locked to any depth of ≥4 km fit the data almost equally well. The best-fitting models indicate a slip rate comparable to the 48 to 58 mm/yr average late Holocene slip rate indicated by offset glacial moraines and to the 54 mm/yr component of relative motion between the Pacific and North American plates that is parallel to the Fairweather fault. No significant contraction was measured across the Fairweather fault. Only a small part of the relative plate motion is transferred across the Saint Elias Mountains to the colinear Totschunda fault. Surveys in 1909--1912 and 1985 of a geodetic network that extends for 72 km across the Totschunda fault indicate right-lateral shear strain is accumulating at a rate of 0.11¿0.06 μrad/yr. This rate of strain accumulation suggests a slip rate of about 10 mm/yr on the Totschunda fault, a value at the lower end of the average Holocene slip rate of 10 to 20 mm/yr. ¿ American Geophysical Union 1987