Pretty simple calcualtion, look at each 30m square in a quad(~212500 of them) and figure out which one has the most difference between its elevation and the elevation of its 8 adjascent squares. So using 30m squares and counting adjascents only, the drop radius is 60m. Geographic error range is for the point is 42m.
Going to a greater drop distance like 100m or 400m would seem like an improvement, but the results get wierd further out, for various reasons.
There is a 'cliff' variation which uses absolute value, as those locations tend to be sides of cliffs. Whereas the steepest point uses drop only - usually a cliff edge, small butttress, or summit.
Have run the SW and NW parts of the state(not error checked):
http://ned-files.com/sanjuans.html
http://ned-files.com/nw.html
More later....