NED_10m	National Elevation Dataset of Iowa, as a 10 meter GRID, Elevation Units in Feet
	NED_FT	National Elevation Dataset of Iowa, as a 30 meter Floating Point GRID, Elevation Units in Feet
	NED_FT_I	National Elevation Dataset of Iowa as a 30 meter Integer GRID, Elevation Units in Feet
	pcnt_slope_i	Percent Slope Model of Iowa, as represented by a 30 Meter Integer GRID
	SPOL_bathymetry_contours	Lake Depth Contours (Bathymetry) of Iowa's Significant Publicly-Owned Lakes