A tornado touched down at Elevenmile Reservoir in Park County on Saturday, injuring five campers as it tore through several campsites and toppled vehicles, some of them occupied, Park County Sheriff Fred Wegener said.

The storm that formed as a funnel cloud high over head hit the state park with little warning about 2:15 p.m., authorities said. Boats and vehicles on the south end of the state park were overturned, including an RV and a pickup with a woman inside. Tents and other camping equipment were flung through the air.

Yet injuries were limited to "bumps and bruises," and the storm missed the more heavily populated section in the north end of the park, Wegener said. The state park has about 300 campsites, and Wegener estimated the park was 80 percent filled.

"If you believe in a higher power, you should definitely thank him because it could have been a lot worse," he said.

The storm prompted a tornado watch for northwest El Paso County that expired at 4 p.m. Saturday. No other tornadoes were spotted, although 1-inch hail fell northwest of Woodland Park as the storm swept across Teller County and through northwestern El Paso County, said Randy Gray, a meteorologist with the National Weather Service in Pueblo.

A strong thunderstorm showered heavy rain northeast of Woodland Park and southeast of Elbert, Gray said.

A severe weather warning in effect for portions of El Paso County expired at 4:15 p.m.

There is a 30 percent chance for more thunderstorms tonight in the Colorado Springs area today.

At Elevemile Reservoir, workers at the park scrambled to warn campers after sighting the tornado, Wegener said, directing them to take shelter in the park's restrooms.

"There was no prewarning. In fact, they got a call afterward saying that you might get some severe weather, but nothing beforehand," Wegener said.

Heavy rain and pea-size hail accompanied the tornado.