The Western Watersheds map shows the arrangement.
The ranchers also benefit from mining operations, in a way you might not expect, as noted at 1:49.
As for the horses, they weren’t considered in the analysis.
The forage assigned to livestock in the allotment is not known and Western Horse Watchers has not yet discovered an equivalent to RAS for the Forest Service.
Forage density (AUMs per year per thousand acres), is a better indicator of carrying capacity than AMLs.