We have used automatic extraction of digital elevation models (DEMs) from stereo imagery of Mars to produce DEMs of parts of the Aeolis quadrangle of Mars. The method uses automated stereo matching based on an adaptive least squares correlation technique, which can be applied to Viking Orbiter imagery. A demonstration of the technqiue is presented, which focuses on the volcano Apollinaris Patera (186¿W, 9¿S), and the channel Ma'adim Vallis (183¿W, 20¿S). The topographic information derived is compared with previous determinations of topography, and a brief discussion of the relationship of the topography to the processes that have acted in the area is given. DEMs derived from stereomatching are an invaluable resource for terrain interpretation, and will provide a complementary technique to direct topographic measurements such as future missions to Mars will provide.