TULSA, Oklahoma - A heads up for drivers who use the Keystone Lake dam west of Tulsa to get to and from work.  The Highway 151 bridge is closing  for at least two weeks. 

Signs are up warning drivers the Keystone Dam bridge will be closed starting Monday, August 22nd. It's not closing for road work, though - instead, an inspection to check the structural stability of the dam.

"Making sure everything's operating as designed," said Earl Groves, Tulsa District Corps of Engineers CEO.

Tulsa District Corps of Engineers CEO Earl Groves says the focus will be on the earthen sections on each end of the dam. They want to know how the soil has reacted since engineers built the dam more than 50 years ago.

"We don't want a surprise, so by doing this we know what the geotechnical engineers have below it, and if there's anything that needs to be looked at further, we'll do that," he said.

Groves says workers will drill a series of small holes in the highway to get to the soil. Then researchers will send down high-tech cameras and equipment to collect data, take samples and check the bedrock.

The new bridge deck which was replaced back in 2014 won't be affected. Groves said workers won't drill any holes in the new concrete.

Other dams have had similar inspections, but this is the first time for this type of research to be done on Keystone Dam. Groves says the tests are precautionary safety measures for a dam that's served its purpose for decades.

 "Very, very smart engineers did this in the '40s and early '50s across the nation," said Earl Groves, Tulsa District Corps of Engineers.

"It was part of the infrastructure building the nation. So they did a great job for it to have lasted this long and many, many years into the future, we hope."

The the bridge is expected to reopen by September first.