I suspect the best resources are always going to be the local guides that are, unfortunately, few and far between combined with digital mapping. My thoughts are, If I were in a local rural area, I would go out on the DR, since it can do highway speeds and go offroad reasonably well, and run some backpack gps software on my phone to record the trip. It's the only way to capture everything. I guess it's one of those things where you also carry a compass and a hard copy local map in case you get lost without a signal. I think the governmental land bureau would have the highest amount of detailed land maps. It makes me wonder if there is any way to access that and if that info is kept in a digital format now days. I have an uncle that does actual map making for a number of map services... Maybe I will reach out to him and find out if there is anything he may recommend for that type of resource.