Binge Grazing at Challis HMA

Now that the roundup is over and the horses are gone, the ranchers can enjoy more of what their allotments have to offer.

In just a few short months, thousands of cattle will be turned loose on an HMA that can only support 253 wild horses.  You see, the numbers won’t work with just hundreds of cow/calf pairs—which is what you might guess for an area that recently achieved a thriving ecological balance.

Refer to Tables 2 and 3 in Appendix G of the Environmental Assessment for the HMA management plan.

In the Bradbury Flat allotment, which covers 15,706 acres and is 100% inside in the HMA, 2,490 AUMs have been authorized on six pastures in a 2.5 month grazing season.

Livestock operators would have to place 996 cow/calf pairs on that parcel to consume that much forage in that amount of time.  The animal density would be 63.4 cow/calf pairs per thousand acres!

The density allowed by plan for wild horses is 1.5 animals per thousand acres.

On Bradshaw Basin, also 100% inside the HMA, ranchers have access to 850 AUMs on 8,184 acres for 2.5 months.  That translates to 340 cow/calf pairs on the allotment with a density of 41.5 cow/calf pairs per thousand acres.

The number of cow/calf pairs on the other allotments and the cow/calf densities can be found in the following table.  The permitted forage for the Mountain Springs allotment was computed by difference, so the column total matched the figure given in Section 4.2.2 in the EA.  The grazing season was not given so it was estimated.

Challis AUM Calcs-1

The chart below shows the forage allowed by plan for horses and livestock on the HMA.

The map showing the allotment locations on the HMA could not be found (mentioned in Section 4.2.2 in the EA) so all of the acreage in the HMA was used in the livestock density calculation.  If some of the land is not subject to livestock grazing, the overall cow/calf density would be higher.

Challis AUM Charts-1

Now you know why over half the horses on the HMA had to be removed.  By the time the ranchers get though, there’s almost nothing left for them.

Never mind that land was set aside for the horses.  That was a long time ago.

UPDATE: If you add the numbers in the ‘Acres in HMA’ column, you get 168,240, which is very close to the size of the HMA stated in the EA (168,720 acres).  Thus, all of the HMA is subject to livestock grazing, except for areas described as ‘Frail Lands.’

RELATED: Challis Roundup Ends.

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