One map, covering the entire Tucson 1 x 2 degree quadrangle at 1:250,000 scale, was prepared as part of a project to test the utility of Landsat-l (ERTS-l) multispectral images to produce maps for practical geoscience applications. They were prepared by inspecting and interpreting many Landsat-l images (bands 5, 6, and 7), from different orbital passes and times of year, of the same scenes. Map-unit boundaries were drawn on 1:250,000-scale enlargement prints of Landsat-l images, on the basis of the clearest evidence of the boundaries from various images. This interpretation utilized information avai12Jle from geologic and soil maps and my own limited field observations as purely secondary input; i.e., the Landsat-image enlargements were used only for plotting information that could be identified from Landsat images. Consequently, the accuracy of this map is constrained by the relatively poor ground resolution and stereovision capability of the Landsat-l images; probably it is adequate for 1:500,000 scale. Tucson 1o x 2o Quadrangle; ease of excavation and potential erodibility--phases 4 and 5. Scale 1:250,000