CUSTER, S.D. (AP) — Thousands of spectators are expected to descend on Custer State Park for the 48th annual Buffalo Roundup.

The Rapid City Journal reports that about 1,250 bison will thunder across the prairie Friday to be herded into corrals. Organizers say the goal is to maintain a balance of bison and rangeland forage. Some of the herded animals will be sold at a November auction.

The event draws nearly 14,000 people annually.

Custer State Park encompasses 71,000 acres in the Black Hills.

Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.