I think that this will be a fairly difficult mutlicache with a little driving and walking. However, you can walk from Stage 2 to the final stage. This could probably also be a puzzle cache, but I felt it better fit as a multi.
At the first stage there is an existing traditional cache. The name of that cache can be used to find the second stage by completing these coordinates: N 32 16.XYZ W 106 42.XYZ. An experienced cacher likely won't have to go to the first stage to acquire the needed information.
At the second stage you will need to combine information provided there with what you already know to move on the the third stage. Don't expect to find the cache exactly at the center of the GZ, after all this is suppose to be challenging.
At the third stage you should see a small cairn of rocks. This cairn is there to let you know that you have successfully reached the third stage GZ, not to hide the cache as that would be too easy. So, no need to search the cairn.
The terrain rating is based upon walking from the Stage 2 parking area. However, with a decent desert vehicle and/or skill one can likely drive closer and the terrain rating would be reduced. This is a desert cache, so beware the usual dangers. For example, the terrain rating would likely be higher if you decide to search for this cache in the afternoon in July or August.
Enjoy the hunt.