Need Help with Generating Contour Lines

Discussion created by psalter on Mar 30, 2011
Latest reply on Apr 15, 2011 by jakubsisak
I am having problems generating contour lines in ArcGIS 10.  Please see the following steps that I have taken and let me know if I am missing something.  (Also I have an attached screen shot of my results.  The green lines are the newly created contour, and the blue lines are the existing contours that do not cover the entire area I need.  The blue lines correspond precisely to a USGS Topo_DRG.)

1.  Downloaded 10 Meter DEM from both the USGS Website and Geo Community
2.  Created a Raster Data Set
3.  Used Mosaic to combine the different sheets I needed
4.  Created Contours for 20' intervals with a Z value of 3.280839895
5.  Contours do not match the DRG/TOPO Lines (The ones in Green)

How do I create contours that are coincident to the 1:24k Topo DRG?

Thanks for your help!