Wind rushes down the hillside, across the grass and through the trees to the river below.

Silence follows.

Then another gust carries the voices of children. A group of nearly a dozen seventh-graders stands on top of a mound covered with grass. The wind once carried the voices of 2,000 Mandan Indians.

Double Ditch state historic site, at first glance, is a grassy hillside along a quiet stretch of river. But dig a little deeper, and it becomes apparent it was a thriving village from 1450 to about 1775. The population peaked at 2,000.

A team of 55 seventh-graders from Horizon Middle School visited the site Friday. The students learned about the village and the Mandan from an archaeologist, planted trees at nearby Eagle Park and did hands-on activities.

"They learn about cultures and how they build up," physical education teacher Gerald Zeimann said. "This set a path for us."

The students learned to grind corn and make pottery, and gathered items for a texture collage. They also played games that didn't require a television or computer, like horseshoes and an arrow toss.

"It's much better than reading out of a book,"Sierra Kreft said.

They stood around an interpretive marker at the site answering questions on a worksheet. The sign held the answers to their questions and provided a hard surface to write them down.

"You get to see it,"Briana Bergrud said.

"And experience it,"Sierra said.

The girls spoke at the same time as they talked about their day at Double Ditch. It was their first field trip of the school year.

They also had the help of freelance archaeologist Amy Sakariasen. She described the society of the Mandan in the village and how people came along later and found out about the village with different types of technology. It started with Bismarck resident George Will, an anthropologist, who used tree rings to date the site, Sakariasen said.

She explained how technology has helped them learn more about the site, such as remote sensing, which helped see that there are more ditches at the site than originally thought.

The students also will write a short story about the area. The activities for the day draw from all subject areas. It's part of Horizon's efforts at integrated thematic instruction, which focuses on themes and shows students how different subjects teach them about the theme.