LAKE OZARK, MO. — On Oct. 16, 1931, workers inside the new Bagnell Dam flipped switches to run current from its big hydroelectric generators. High-power lines strung through dense, hilly forests carried power to a big feeder station in Wellston and to present-day Park Hills, in Missouri's old Lead Belt.

Back then, Union Electric Light and Power Co.'s dam on the Osage River was hailed for its power to make electricity. A few rough fishing camps popped up along the dam's creation, the Lake of the Ozarks. But it would take almost three decades to turn the 60,000-acre reservoir into a bustling summertime playground.

The Osage hydro plant originally produced 139,000 kilowatts, providing a hefty 22 percent of Union Electric's total output. Today, the much-upgraded plant generates about 234,000 kilowatts, or barely 1 percent of the capacity of Union Electric's successor, AmerenUE. Hydro power is an afterthought, drowned by the buzz of seaworthy pleasure boats.

Union Electric bought rights to the dam site from a failed Kansas City company. The place was a narrow spot between the bluffs of the Osage, four miles from the village of Bagnell. UE began construction in August 1929. The project had a payroll of more than 3,000 lucky men who earned 35 cents an hour and lived in company bunkhouses — room and board deducted from their pay.

The $30 million dam would be 2,543 feet across, 148 feet above bedrock and consume 551,000 cubic yards of concrete. (Lambert-St. Louis International Airport's new 9,000-foot runway needed less than half that volume.) The lake began filling in February 1931.

Among the settlements in its way was old Linn Creek, former seat of Camden County, where many residents opposed the gathering inundation.

UE paid $60,000 for a new courthouse in Camdenton. By 1934, thanks to the dam, the county could cut its property-tax rate. Locals charged fishermen $1 a night for primitive lodging, some built to look like teepees.

By 1942, boosters could boast of $1 million in tourism business. There were traffic jams that summer along Lake Ozark's arcade strip. One decade later, the lake was home to more than 350 resorts.

Luxury came in the early 1960s, first with the Tan-Tar-A resort and then Lodge of the Four Seasons. Regular folks could still play Skee-ball and ride go-karts, but the 1,150 miles of shoreline began filling up with big homes, more resorts and condos. Today, about 16,000 condos crowd long stretches of the shore. The lake generates $202 million annually in tourist trade.

And you can still play Skee-ball.