Distance
5.4 mi to summit
11.3 mi total
Elevation
5,872 ft start
6,976 ft max
Vertical
2,947 ft gain
Time
4 hr 8 min to summit
8 hr 11 min total
I went by back way (from Lovell) to check new route from ridge. In short, the old routes work best
hwstock
https://edits.nationalmap.gov/apps/gaz-domestic/public/gaz-record/845609 (feature ID 845609) is the USGS place name and coordinates (36.1080189, -115.4902738) for Rainbow Mountain, listed as 6811'. The coordinates given are slightly WSW of the highest point (where the register is located). This summit was called Rainbow Peak by Branch Whiney (to distinguish it from Rainbow Wall), but is called Rainbow Mountain on Peakery and Peakbagger. No optical survey of this point is indicated, and the elevation is likely an estimate from photogrammetry. NAD88 calculations dropped the elevation estimate slightly.
hwstock
The fastest way to climb is by the "Rainbow without the ledges" route; that route used to be considered class 4, but abundant handlines have sprouted over most of the hard parts.