I created a mosaic of several 10m DEM that cover my study area. I clipped the mosaic to the study area. When trying to run the DEM reconditioning, the program got hung-up. Yesterday I ran the program with a single DEM before I made my mosaic and it worked well and fast! If there is a size limitation, what are my options? Ultimately, I want to determine drainage area above particular point locations along in a watershed. Do I need a DEM for an entire watershed?