Thanks Jim for the info. The person I taught with out at Philmont makes his own maps and owns a company called Timely Topos. He had a laptop device that was around 20K and had a GPS built in. He could strap the laptop around his waist and neck and walk around clicking things as he went to make a custom topo. It was very cool! I will check out the site. I use the topos you made for Mark Twain all the time in ExpertGPS. Mike ----- Original Message ----- From: Jim Bensman To: geocaching@xxxxxxxxxxxxx Sent: Tuesday, July 29, 2008 6:26 PM Subject: [GeoStL] Re: Flooding in northeast MO You download the elevation and hydrology data from USGS servers. The hydrology is in a format you can use directly. The elevation data (which is 3 times more accurate than what is on the USGS 24K maps) has to be run through a freeware program to turn the geotiff into a file with contour lines. Then there is another freeware program you compile the map in. There is a steep learning curb, but once you figure it out, it is pretty easy to do. It probably takes 15 to 20 minutes to make a map (that does not include the time the computer is compiling and converting). Here is a description of the process I use: http://home.cinci.rr.com/creek/garmin.htm Jim Bensman "Nature Bats Last" Go Obama!