Staying found on the Great Divide Mountain Bike Route has been easier than I expected. But perhaps it's because I followed the Adventure Cycling Association's recommendation of having multiple modes of navigation handy.
I am running a Cateye Strata Cadence cyclometer, which is a wired version of their Strata. Using wired technology allows for a much longer battery life in the cyclometer. Installation was easy, and I've found it very easy to use. You can customize the wheel diameter of your bike to make sure your distance readings are accurate, which is very important for following the ACA maps. However, I've found that being a few centimeters off is acceptable as long as you are aware of the difference between the ACA map mile and your cyclometer. Not to mention, there's no way to "add" miles to the Cateye distance reading (like in a car you have Distance 1, Distance 2, and the Odometer). But as long as you zero out your trip distance at a reasonable mile marker, adding the miles in your head is easy.
An example: the ACA map says at mile 150.3 you will "cross a cattle guard", you might zero out your computer then and just continue to mentally add 50 miles to the rest of the directions that day. However, I wouldn't recommend using a generic mile marker like this, because the maps tend to arbitrarily chose one cattle guard or railroad tracks out of multiple. So something more significant like signs, landmarks, or obvious intersections are better.
Without going off the deep end, I'm going to say that the Garmin eTrex20 would've been a good device if I hadn't accidentally deleted the base map using Garmin's own software. Call me stupid, but I don't think one should be able to delete the basemap. Additionally, to get the topo maps for the divide, it would've cost an additional $200. (Because really the basemap isn't useful enough for navigation in back country.) So with a completely black background, I downloaded the waypoints into the GPS and then proceeded to find a better option.
The Gaia app for the iPhone seemed to fit the bill. I took the Garmin with me just in case, but I haven't used it once. The Gaia app takes a little learning to use it effectively, but it's very effective. You can download sections of an already loaded topo map for offline use, load the entire GDMBR routes and services waypoints, and it will be able to locate you on the map without cell phone coverage.
So for $30, I get everything the Garmin would've offered for $400.00. A smart phone uses the same GPS satellites as a Garmin device.
The only trick is to keep the cell phone charge, which hasn't been a problem so far wth the generator hub.
I am keeping the GPS around in case it's too hot in Wyoming for the iPhone to stay on.
The Adventure Cycling Association's naps are excellent if you want to follow their route exactly. The maps will inidcate some alternatives to particularly difficult sections, and will give some detail on additional roads but not enough to rely on. Hence, the GPS/Gaia app.
Here's to staying found.