CUSTER STATE PARK - The breeze gently stirred the tall grasses as pickups carried members of the media on a special tour of the Custer State Park Buffalo Herd Sunday morning.

"You are going to get a chance to see these animals out on the prairie, up close and personal," said Craig Pugsley, visitor services program manager for the park.

He wasn't lying.

For two and a half hours, three park vehicles with videographers, photographers and others, were able to experience the massive beasts out on the prairie, much like they were 150 years ago, when the plains were covered with their wooly, dark brown bodies.

"We actually did the pre-roundup Saturday," said Custer State Park wildlife biologist Chad Lehman. "We pushed the herd from the southwest corner of the park over here to the east side, nearer the corrals."

Today the parks crews and other helpers will push around 600 bison into the corrals along the Wildlife Loop in the park. The event will be witnessed by about 12,000 visitors.

"That part only takes about an hour," Lehman said. "But we give the herd a chance to settle down today after Saturday's push, and before Monday."

The Custer State Park Buffalo Roundup has received international attention in recent years, as live webcasts have let the world get a glimpse of what takes place in the event. Over the years, the roundup has grown to include an arts and crafts fair and a chili cook-off, along other activities designed to bring visitors to the park at the end of the vacation season.

But when it comes right down to it, the roundup is a management tool.

"We need to cull out some of the herd; to get it back to a proper size for over the winter," Lehman said.

The herd that is pushed to the corrals this morning will join a smaller herd of about 200 bison, which was rounded up last week and has been held in the corrals. After the large group is moved, the smaller group will be "worked" by parks employees and veterinarians, Lehman said. They have been able to settle themselves and it gives visitors a glimpse of the inner-workings of the park.

"We draw blood for TB and Bangs testing," Lehman said. "That usually takes about three weeks to get the test results, then after that, the vets clear them for sale."

This year's Custer State Park buffalo sale will take place at the corrals on Nov. 15. Lehman said around 250 head will be sold at the auction. Other means of herd reduction include an Internet sale and a special hunt for older buffalo in the park.

"We will probably keep a few head more than in previous years," Lehman said. "We have had more moisture this year and there's still quite a bit of grass standing."

Lehman said that there are about 1,200 buffalo in the park, but not all are rounded up. The older, mature bulls are not rounded up, as they would injure smaller animals if they were confined in the pens. "Plus, they don't fit through the chutes," said park bison specialist Sterling Smith. The roundup concentrates on cows and calves, along with younger bulls.

"We will sell off quite a few yearlings and such, along with some 2-year-old bulls," Lehman said. "We do the blood draw and weigh the animals, and do fertility tests on the males. The ones that test out well will probably be sold as breeding stock and the rest will be sold for slaughter."

Among the herd, the immense size of some of the mature bulls was much more apparent. They meandered along a trail through a small meadow to a watering hole. While the herd was wary of the pickups, it did not bolt and run. Grunts emanated from throughout the herd, in a wide array of tones - from the young calf searching for its mother to the low rumbling of a 10-year old bull - who was just making conversation as he made his way through the herd.

"That's quite a picture, isn't it?" asked Lehman, as the group looked down on the milling herd from a vantage point high above. It certainly was; one that may have been experienced 100 years earlier from the same bluff, on a sunny September morning.