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1985 was the year the RockHopper was rolled out, as one level below the StumpJumper Sport (and at $400 vs. $500).

The following year, 1986, the Sport model was dropped, and the RockHopper acquired nearly all of the higher-end features of the retired Stumpjumper Sport model.
Upgrades adopted from the Sport model included DB tubing, Wheelsmith spokes, full M700 XT (friction) componentry and the anodized model of Specialized touring crankset.
The welded-only (no bikini crown) fork and sloppy frame welding stayed onboard on the '86 RockHopper, but the componentry was almost entirely high-end.

Great photos of you in the desert, Rockbopper! Those were great bikes and are still.

1987 saw broad use of the new S.I.S, 6-speed XT gruppo, which was a very big deal in the upper-end range MTB market.

The under-chainstay brake was widely applied in '87, and these can be tricky to service (pivot spring adjustment in particular) but can work extremely well in clean conditions when the straddle cable is shortened. The cable path is very direct and with only the front length of cable housing to add any flex to the rear brake's heavy-duty (1.9mm) cabling.
Often these same vintage of bikes will also benefit hugely from a crown-mounted cable housing hanger as a way to all but eliminate front brake judder (due to steerer flex feedback into the tensed cable).