Authorities are investigating an apparent sexual assault that forced the lock down of a state park near Waterloo and Cedar Falls on Tuesday (July 28, 2015).

George Wyth State Park was shut down for several hours after a woman was found unconscious off a trail in a wooded area near the park's campground. She was taken to a hospital for treatment.

Park rangers, the Iowa State Patrol and police officers from both Waterloo and Cedar Falls responded to the call around 3 p.m.

Believing the suspect was still inside the park, authorities closed all vehicle and trail entrances to George Wyth and required everyone to show identification before they were allowed to leave. Authorities used motorcycles and All-Terrain Vehicles (ATV's) to search the park, but didn't find the man.

Late Tuesday, Waterloo police said the suspect remains at large. They're asking for the public's help in identifying a white man with lighter color hair, who's in his 20's. He may have an irritation from poison ivy and, possibly, scratches to his arms and facial area.

Anyone who has seen a person matching the suspect's description should call Waterloo police or Cedar Valley Crime Stoppers. Authorities say anyone who was in George Wyth State Park on Tuesday should also report anything that they believe was suspicious in nature.

Waterloo Police Department can be reached at 319-291-4340, Extension 2. Cedar Valley Crime Stoppers can be reached at 855-300-TIPS (8477). Tips may also be left at www.cvcrimestop.com. A cash reward is available.

Tips may also be sent with TipSoft or by texting the word CEDAR plus the information to CRIMES (274637). Message and data rates may apply. Text STOP to opt out at any time. Text HELP for more information.

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