Though not all soil surveys are online, it's possible to find many via this site, provided through the National Resources Conservation Service. If you're new to soil surveys, NRCS provides this definition: "Soil surveys furnish soil maps and interpretations needed in giving technical assistance to farmers and ranchers;
in guiding decisions about soil selection, use, and management; and in planning research and disseminating the results
of research. The surveys also are used in educational programs about soil use and conservation."
