I have a few uses for scanning large mountain areas
-We have one volcano in this region of the world that has a lake in the crater at the top. Every now and again the volcano pushes up and spills the lake over the crater edge. Accurate models of the mountain have been made to model how this resulting Lahar(volcanic mudslide) will travel down the mountaIn and what areas will be effected.
-A ex lecturer of mine was using photogrammetry to model snow levels on mountains so power companies producing Hydro Power could predict how much water they would get in the spring melt
The same professor also measured mountain heights of our Alps using photogrammetry and them proved his results with conventional GPS
http://www.otago.ac.nz/surveying/staff/otago027774.html-there are some government bodies that are interested in scanning large areas of land for modeling coastal erosion. Done correctly photogrammetry can produce results quicker than LIDAr(or so i am lead to believe)