LITTLE ROCK, Ark.—Public tours at one of the largest dams in the southeastern United States have resumed — but on a limited basis because of continuing security concerns after the Sept. 11 terrorist attacks.

The powerhouse at Bull Shoals Dam was among the first hydroelectric plants of the U.S. Army Corps of Engineers to conduct regularly scheduled tours since the attacks nearly seven years ago, district spokesman P.J. Spaul said.

The hydroelectric plant and four other plants the corps operates on the White River produce enough electricity to light 170,000 homes, or 1.7 billion kilowatt-hours, Spaul said.The dam was one of the largest engineering projects ever undertaken when construction began in 1947 — initially just for flood control. The Bull Shoals Dam stretches 2,256 feet across the river, rises 256 feet from the streambed and holds about 2.1 million cubic yards of concrete. Each day, except Mondays, groups of about 15 can tour the powerhouse. If You Go...

•BULL SHOALS DAM: Bull Shoals-White River State Park in Arkansas; http://www.arkansasstateparks.com/bullshoalswhiteriver. Tour schedule: 1:30 p.m. Tuesday and Thursday, 10 a.m. Wednesday and Friday, 10:30 a.m. and 1 p.m. Saturday, 11 a.m. and 1:30 p.m. Sunday. No tours Mondays. Cost: $2.50 for adults, $1.50 for children, ages 6-12. Tours are free for children under 6. The corps plans to offer the tours at least through Labor Day weekend.

• GETTING THERE: The dam and lake are located near Mountain Home on the Arkansas-Missouri border. From I-40 in central Arkansas, take U.S. 65 north to U.S. 62 east and proceed to Marion County. From I-44 in southern Missouri, take U.S. 65 south to U.S. 62 east.

• BULL SHOALS LAKE: Aside from the dam, Bull Shoals Lake, the largest in Arkansas, covers more than 45,000 acres and is hugely popular among campers, boaters, swimmers, scuba divers and others looking for outdoor recreation. The cold waters released from the dam create trout heaven for anglers along about 60 miles of the White River.

• VISITOR CENTER: At the state park’s James A. Gaston Visitor Center, exhibits tell the story of the White River and the dam. Built for $4.8 million and opened in 2006, the center provides a panoramic view of the dam, the lake, the White River, and the Ozark Mountains. It features aquariums, observation decks, water features, and a butterfly garden.