I'm almost afraid to mention how poorly I think missing persons cases are handled out in the desert. Big stretches of federal land (defunded, no enforcement - BLM, NP, NM)...completely no man's land. Overburdened local county Sheriff (tremendously large region, much of it not under Sheriff's jurisdiction except by default - no tax revenue commensurate with the large area and its propensity for crime).
Sex offenders migrate out there. Weirds in general (amongst all the other nice people of course - but it's a cheap place to live, lots of places where a person can squat if they know what they're doing, many sinister actors, IMO). SBCSO does its best, but these missing person cases can only use up so many resources (fire management right now is huge - and yes, takes LE to help and there was one heckuva big one on federal land out that way).
It's going to take a private investigator or some fine sleuthing to solve this one. Most JT area MP cases are solved by members of the public (or family) finding or stumbling upon the body...often way later than we'd expect (the Amboy Crater couple is a good example).