As the first hard rain of the spring pelts down, five bison bulls at Cerro San Cristóbal Ranch prance and dance in the mud, like school children at recess.

Nearby, a dozen bison females locate their month-old calves and, like mothers everywhere, circle up around them for protection.

The young calves, all legs at this age, lean heavily into their mothers' matted, gnarly coat. A few nuzzle up to a nipple for a quick hit of milk.

Theirs is a matriarchal society: Adult females run the show, fostering both a strong instinct to stay together as a herd and a distinct pecking order among the mothers. The bulls show up for the rutting season, then they are shunned, left to roam and graze and butt heads for most of the year.

"They stay glued together for the first six, seven months, and they don't like the corral much, " said ranch manager John Painter.

Yet, when Painter approaches with pellet snacks, the cows stick their noses through the iron rails and greedily take pellet after pellet from his hand.

The calves keep their distance, wary of the strange, two-legged beasts on the other side of the fence. Any sudden noise or gesture sends them back to the shelter of mother and herd.

"When I'm dealing with them, I think of how I deal with humans," says Painter, who has been on the ranch owned by Alfred and Natasha Keller since 1992. "I stay mellow and approach like I don't care. It's a mental battle between us. They've got a lot of human mannerisms."

The Kellers formed the Montoso Bison Co. in 1986, just as the nutritional value of low-fat bison meat became more widely known.

"It was profitable until the 1990s, when the number of ranches went up and the bubble burst," said Painter. "Prices dropped, and the National Bison Association began to aggressively market."

Despite rising demand among restaurants and supermarkets, a small producer still struggles against drought, and high feed and diesel prices, Painter said.

Ideally, bison can get enough feed on the natural gramma and Western wheat grass that grows between the sage bushes on the 7,400-foot-elevation range. Winter range is supplemented by hay. Like a cow, they have four stomachs that digest their food. Occasionally, Painter will brush-hog a couple of acres to let the grass grow thicker.

However, during drought cycles, the rancher must purchase more hay, a commodity that is also high in price.

Staying grass-fed and shunning hormones or stimulants keeps Montoso bison in a specialty market. Painter doesn't brand, castrate or de-horn the animals, like some producers do.

Bison have been renowned as a multiple-product animal. The meat comes from yearlings, aged 20 to 24 months.

All of Montoso's meat goes through the G&C Meat Packing plant in Colorado Springs, the only federally inspected plant in this region. There, it is butchered, packed and frozen for sale.

"I love working with them because they are so smart," said Painter. "They are dangerous but you can build a relationship with them."