20210303 14563700 1.0 TRUE Steep Slopes (20% or Higher) Polygons representing slopes greater than or equal to 20% in the Portland urban services boundary area. Derived from 2014 3' resolution LiDAR bare-earth digital elevation model (DEM). All slopes average over a horizontal distance of 15'. Minimum area of contiguous slope is approximately 1/2 acre. Polygons were created, generalized and smoothed in ArcGIS 10.3.1.