I know you found the answer, but let me suggest for trails and most "Off-Road" planning---use Tracks vs Routes. My understanding is Routes are mainly for roads--something the map can "follow" to plot your route. Tracks can be for anything. Tracks were originally intended for you to "record" your trip--but now we have lots of downloadable .gpx files to get our maps of trails, etc.
I too have an O450, and it works great with the .gpx files i download. And if you have the heartrate and cadence monitors, the O450 will save that info too.
The TOPO24K West maps that I have appear to allow you to select known trails as a route. Now I know they are going to be approximate but it should suffice enough for us on our dirt bikes to plan a route and find trail heads.
I also grabbed NWTrails off of switchbacks.com. Those are tracks people have laid. They are surprisingly close to the trails in the 24k TOPO maps.
I should have mentioned---You must draw your own Tracks (or download a .gpx file if you can find what you want) in BaseCamp. It is simple to do with the "New"\ "Track" pencil, but it does take a bit of time. There is no automatic "routing", but the length of your Track will be displayed.
then save it as a .gpx file, Send it to your O450, and if you want--Import it into Google maps to share with your buddies with a satellite view. pretty nifty :)
