Indian Grinding Rock's roundhouse is used for dances. Bee photograph/Janet Fullwood

PINE GROVE -- Year after year, for century after century, women of the Miwok tribes gathered at an outcropping of marbleized limestone in what is now Amador County to grind acorns and other seeds into meal. Over the generations, their stone pestles bit into the rock, slowly boring almost 2,000 cupped depressions into its surface.

Then came 1848, the Gold Rush and the arrival of men who had traveled thousands of miles to find their fortunes. The miners didn't know -- or care -- about the cycle of native life that revolved around the chaw'se, or grinding rock. They diverted the stream that ran by it, introduced disease, turned livestock out in surrounding meadows and grew crops on the land where the Miwok had hunted and gathered for their subsistence. Within a few short seasons, the American Indians were forced out of their traditional patterns of livelihood.

The grinding rock survived, however, and today is the centerpiece of Indian Grinding Rock State Historic Park and Chaw'Se Regional Indian Museum, a place where visitors come to learn about Miwok culture and the painful period in history that brought about its demise.

"The story here is a sad story because the Gold Rush forever changed the life of the Miwok, who were pushed out of lands they had occupied for centuries," says supervising ranger Curt Kraft.

"Native people," he adds, in reference to California's much-ballyhooed Gold Discovery to Statehood Sesquicentennial, "do not celebrate the Gold Rush."

The park and its impressive museum instead tell the story of traditional life and the invasion of the wilderness by John Sutter, who built a fort at Sacramento in 1839. A Sesquicentennial exhibit -- "Gold, Greed and Genocide," will be installed later this year.

"My favorite motto for the park," says Kraft, "is that through knowledge comes understanding, and through understanding comes respect.

"Ultimately, what we try to do here is teach respect for native American culture."

One of the park's best teachers is Steve Walloupe, 22, an interpretive ranger whose thick black ponytail bespeaks his Miwok ancestry. Walloupe grew up listening to his grandmother and great-grandmother spin stories about the old days. His great-grandmother, Mabel Walloupe, now 94, "is one of the last alive to speak the Plains Miwok language," he says in a voice tinged with both pride and regret.

Walloupe often guides groups of schoolchildren through the park, shepherding them past museum displays and demonstrating the use of artifacts ranging from hide-covered game balls to porcupine-tail hair brushes -- all in an attempt to get the kids to realize how Miwok culture was similar to their own.

On this drippy day in April, however, the class scheduled to visit the park has canceled, leaving Walloupe free to answer questions posed by the small group of adults who stand on a wooden observation platform overlooking the grinding rock. Its 1,185 mortar cups are filled with rainwater that reflects the leaden sky and emphasizes the sense of vanished community that permeates this haunting place.

Walloupe explains that this particular chaw'se bears the largest number of grinding cups on any single rock face in North America, and that it's also significant for its petroglyphs. Some 363 decorative carvings -- circles, spoked wheels, animal and human tracks, geometric patterns -- can faintly be seen etched into the gray limestone. Such markings, says Walloupe, "are not known to exist in combination with grinding cups anywhere else."

"Everything's an estimate when it comes to dates," he continues, explaining that while the petroglyphs are thought to be around 3,000 years old, the oldest grinding cups could possibly be five times older than that.

Not far from the grinding rock, down a path that meanders past magnificent valley oaks, some of them more than two centuries old, are a cluster of cedar-bark shelters built in the Miwok style. Beyond is the roundhouse, where ceremonial dances are held each September during Big Time, the traditional acorn harvest thanksgiving still observed by California tribes.

After a rainfall, the cupped depressions used for grinding seeds become miniature ponds at Indian Grinding Rock State Historic Park in Amador County. Bee photograph/Dick Schmidt

Topped with slabs of cedar bark, the circular structure -- one of the largest roundhouses in existence at 60 feet in diameter -- is dug into the ground, supported from the inside by cedar poles woven with wild grapevine. Four enormous oak floor posts stand sentry at each corner of the clay dance floor. Visitors are requested not to touch.

"Everything about the dances has to do with the number four," Walloupe explains of the rituals performed here. "Four dancers, four poles, four directions... traditionally, they danced for four days and four nights, in four sets of four songs each."

A remodel of the roundhouse five years ago included the addition of a fire exit at the rear of the structure -- an alteration required by the state, but one that Walloupe says disgruntled many in the Miwok community.

"Lot of people won't even come inside here anymore -- they feel it's been ruined. The circle represents Mother Earth. It's not supposed to be broken."

Nevertheless, the place is packed with spectators during the Big Time dances -- "which are not like the powwows people think of," Walloupe says. "It's lots of chanting, over and over, with clapper sticks and foot drums."

The Big Time dances are also some of the only Miwok ceremonies in the Central Valley open to the public.

There's more to see and learn in the park's excellent museum, whose two-story architecture echoes that of the roundhouse. The collection includes hands-on exhibits for kids as well as examples of basketry, feather regalia, jewelry, arrow points and tools. The interpretive signs and historic photographs that accompany the objects in the cases explain the history and the traditions of the native people, as well as the impact of the Gold Rush on the culture and environment of the area.

Not to be overlooked are the park's 23-site, first-come, first-served campground (not on the state reservation service, by the way) and an "environmental" group campground where campers sleep, Miwok-style, in bark shelters. A self-guided nature trail and a longer hiking trail wend through through magnificent stands of oak trees and past ditches, ponds, dams and other evidence of 19th century mining activity.

"We get lots of frogs out here -- and also lots of mosquitoes," notes Walloupe.

Maybe so, but most visitors would agree that the tranquil setting is worth a bite or two.