I found this report of her sightings and purported route.
Melanee was found near the horizonal grey line at the top of the page which would be Highway 50, at the border between Nevada and Utah.
Now how would a Chevy Malibu have been able to handle those roads into that area?
If this is accurate, then it would have been a substantial detour from the purported sightings in Primm, NV, St George, UT, or Panguitch, UT to the area where Melodee's remains were found.
Primm NV to Baker, NV is about 5 hours, then another 40 miles to the Slot Canyon area
St George, UT to Baker NV is about 3 hours, 189 miles, then another 40 miles to the Slot Canyon area
Panguich, UT to Baker, NV is about 2.5 hours, 160 miles, passing by the Gandy Ranch turnoff on the way there.
So, if the sightings are correct, then LE needs to check out the timing of that St George and Panguich sightings. I've driven Highway 50 across Nevada, passing by Panguich on the way to Bryce Canyon NP. There is a cutoff that bypasses Highway 50 and has few areas where there would be CCTV. Not sure she would be that savy. More like she made for Highway 50 and then went west to the Slot Canyon site.
St George is on the fast I-15 highway, but Panguich is on Highway 89, not I-15. That's a weird jump if you have taken a detour to the Ely area.