KETCHUM, Oklahoma - A plane flown by Senator Jim Inhofe ran off the runway Sunday evening at South Grand Lake Regional Airport. 

According to his office, Senator Inhofe was out flying with another local pilot in two separate planes. Due to bad weather, Senator Inhofe was forced to land at South Grand Lake Regional Airport when the mishap occurred.

His office said the 81-year-old Republican walked away and is now at home with family celebrating the July 4th holiday.

It's not clear why the airplane ran off the runway. The OHP is investigating.

The airport director said the airplane is a Harmon Rocket, a small, single-engine propeller-driven airplane that was built in 2003, according to FAA records.

Inhofe has been a pilot for decades and is a member of the U.S. Senate General Aviation Caucus.

The senator caused controversy in October 2010 when he landed on a closed runway in Port Isabel, Texas.

The senator did not admit to any wrongdoing, but the Federal Aviation Administration required him to undergo remedial training after that incident to avoid more serious punishment.

In 2006, Inhofe had a mishap while landing at Jones Riverside in the Tulsa area.

No one was hurt in that incident.

In 1999, the propeller fell off a plane he was piloting near Claremore. He shut the engine down and made a safe landing at the Claremore airport.

Inhofe's son, Dr. Perry Inhofe, died in a crash when the airplane he was flying went down in Owasso in 2013.

Dr. Inhofe's wife filed a wrongful death lawsuit over that crash.

Last year Inhofe told generalaviationnews.com he owns several airplanes and has been pilot for more than 60 years.