I have DEMs I got from USDA. In QGIS, the range of values for one of the DEMs is 112.661 to 158.197. In Arc, the same DEM has a range 109.206 to 178.305. Why is this? The CRS is the same for both, NAD83 UTM 15 N. I am using QGIS 2.2 and Arc 10.1. John