Hi - I'm new to this and I also want to thank all the posters for their great and useful advice. I have an OR 450 and (thanks to the helpful tutorials) I've successfully loaded the NY topo and MyTrails on my unit. I was thinking that a huge advantage of these maps would be that I could mark a waypoint on the trail (such as the top of the mountain) and have the GPS tell me the trail distance to the waypoint. however, when I've tried it, the GPS appears to give me the straightline distance instead. I'm just using a simple method - marking the waypoint on the map. Is there something else I need to do? Thanks for your help.
Unfortunately there is nothing else you can do because this is not a routable map.
Well, that's a little disappointing, but I think I figured something out that will do what I'd like. I made a route which covers the trail I'm interested in. When I was creating the route, some of my waypoints were slightly off the My Trails trail because they were not labelled as the trail - they were labelled with an elevation instead. So, that gave me a good trail distance (compared to my guide book). Then I tried to view an elevation plot and got the message "Route Calculation Error" - what does that mean? (I agree with several other members that Garmin's documentation leaves much to be desired) I thought it might be because not all my waypoints were on the My Trail - but they all had elevation data - so why doesn't it plot? Thanks again for your help.