While we do recommend some Apps for your Smart Phone, there simply is no perfect replacement for a good old fashion Paper Map. There are plenty of great paper maps available, there are two that we HIGHLY Recommend, a copy of the Forest Service MVUM for the respective District you will be traveling in and a GOOD Topographic Map.
With these two types of Maps you will always have the all so important information when needed. The MVUM will give you the information on what FS Trail you are on and a possible route to get out or relay information to others if you are in need of assistance. The Topographic map can also be important, as it will show you the type of terrain you are in enabling you to plot a course that will be easiest to follow.
With that being said you will find the Apps we recommend below. You can also visit the Interactive Map above and find the Ranger District for the Area you will be in and obtain an MVUM for that District at their Office: