Through every brushstroke, every dab and detail, Sarah Penney had the wisdom of untold centuries to guide her hand.

"In every aspect of the painting, I had advisers," says Penney, a Lapwai artist who recently completed 15 murals depicting the lifestyle and culture of the Nez Perce people for "The Nez Perce: Since Time Immemorial" exhibit opening Thursday at the Lewis-Clark Center for Arts & History in Lewiston.

"It was imperative to give an accurate historical portrayal of the Nez Perce people," Penney says.

Sometimes that meant calling Josiah Pinkham of Nez Perce Cultural Resources to come to her house late at night and make sure the depiction of a traditional horse saddle was done right. Other times it meant waiting while several tribal committees and councils gave their approval.

But it made the daunting task of creating the murals in only four months a bit easier, says Penney, 32.

"They were a Godsend to me. I felt (this project) was a very large responsibility because a lot of people will see this and relate what they saw back to the Nez Perce."

She still managed, however, to get a little bit of herself into each mural.

"I like faces, and I like to show multiple generations, family and love in my work," Penney says, pointing to a wall-sized painting of women gathering camas roots.

A grandmotherly woman is in the center, holding a traditional basket of camas. Behind her, women and girls hold hands and gather more roots.

"I just had to get a baby in this one," Penney says, pointing to an infant sleeping on a woman's shoulder in a mural titled "Ha'ham Hipa'axamcix" or "Men War Dancing."

In another, Nez Perce ride two to a horse across a prairie backlit by a deepening Idaho sunset.

In reality, each Nez Perce would probably have his or her own horse, Penney says.

"But I wanted to show people together," Penney says. "That's me."

Penney, a Nez Perce/Santee Sioux and enrolled member of the Nez Perce Tribe of Idaho, was chosen in January to create the murals for the exhibit on display at the center through December 2006.

"Nobody knows me as an artist," says Penney, who grew up on the Santee Sioux reservation in Flandreau, S.D. "I usually just do it for family, for Christmas presents."

Penney considered studying art in college. But her father convinced her to pursue other avenues.

So she made art a hobby, painting in her brightly colored realism style for friends and family while she earned her bachelor's degree in child development and family studies from South Dakota University. She later earned a master's degree in education at the University of Idaho.

Her passion now is her work as an educator at the UI, where serves as director of the UI Teacher Recruitment Program and special assistant for Native American Affairs within the Office of Diversity and Human Rights.

But the mural project enticed her, as an artist and a Nez Perce woman.

"I was very honored to receive this commission," Penney says. "I had never done anything of this magnitude."

Little did she know the extent of the task she had undertaken.

"I am so glad it is done," says Penney, who put her life on hold and worked many long nights and weekends to complete the project.

The exhibit takes the visitor "from creation to the present," says Carlton Oakes, center director, of the exhibit, which was created through a grant from the Idaho Governor's Lewis & Clark Trail Committee.

Located in the upstairs center gallery space, the murals begin with a painting titled "Titwa'atit" meaning "Story."

The illuminated faces of six Nez Perce children gaze up at an elder enrapt in the telling of a tale.

This was one of the hardest to create because it was meant to represent creation, and the Nez Perce traditional education, the passing on of stories, religion, culture and practical information, Penney says.

She decided, at last, on an image that makes the viewer feel part of what is happening in the painting, the passing on of the ancient stories in the oral tradition.

The rest of the murals take the viewer on a journey through three aspects of Nez Perce traditional life; the water culture, horse culture and daily life.

The room of water culture paintings depict fishing and netting eels on the Clearwater River. A man rides a horse through water, a traditional breaking method, and tribal members ride appaloosas on the prairie in the horse culture room. Morning meals, ceremonies, council meetings and the root gathering mural follow in the room of daily life murals.

"These are all representing Nez Perce life precontact, or before (Meriwether) Lewis and (William) Clark," Oakes says.

Photographs, posters and other items depicting modern-day Nez Perce culture will be displayed in two adjoining rooms.

The tribe, who worked closely with the center on the project, felt that showing Nez Perce culture is still vibrant was important, Oakes says.

"It is not just a thing of the past," he says.