CUSTER, S.D. (AP) - Bison buyers are set to descend on western South Dakota's Custer State Park.

The park's annual buffalo auction is Saturday and features a sales list that includes 43 2-year-old pregnant heifers, and another three that aren't pregnant. Sixty-two bull calves also are for sale.

They're among the 256 bison to be sold starting at 10 a.m. MST to buyers nationwide. The goal is to thin the park's herd, which officials say is especially important after a mild winter and dry summer left the grassland parched and at risk for over-grazing.

Park Resource Program Manager Gary Brundige (BRUHN'-dihj) says that officials decided to sell more animals than initially planned because of the summer's drought.

The auction follows September's jaw-dropping, internationally famed buffalo stampede that draws thousands of spectators.

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