The stocking rate allowed by plan in the Paisley Desert HMA is 0.5 horses per thousand acres. Given a forage requirement 12 AUMs per year per horse, land designated for them must be able to produce 6 AUMs per year per thousand acres (AUMTA).
The HMA is also designated for permitted livestock grazing. Allotment numbers are shown in the following map. The HMA boundary appears in red.
At Squaw Lake, #0418, 834 AUMs per year have been assigned to livestock on 41,354 acres, for a production rate of 20 AUMTA.
Saint Patricks, #0419, offers 750 AUMs per year on 25,674 acres, for a production rate of 29 AUMTA.
Sheeprock, #0428, provides 3,967 AUMs per year on 146,278 acres, for a production rate of 27 AUMTA.
These parcels can only produce 6 AUMTA if you’re talking about wild horses.
What about the neighboring pastures?
Allotment #0426, on the southwest side of the HMA, offers 1,021 AUMs per year on 47,850 acres, for a production rate of 21 AUMTA.
Allotment #0420, on the northwest side of the HMA, provides 1,056 AUMs per year on 21,882 acres, for a production rate of 48 AUMTA.
Allotment #0430, on the east side of the HMA, has 4,202 AUMs per year on 43,654 acres, for a production rate of 96 AUMTA.
What can you conclude about these numbers? Land is much more productive when it’s designated for livestock. Productivity drops sharply when it’s earmarked for horses.
That’s why AMLs are small and true AMLs are much larger.