TULSA, Oklahoma - The 38th annual Tulsa Run is underway. More than 4,500 runners are challenging themselves with a 9-mile race course Saturday cutting through parts of downtown and midtown Tulsa.

Overcast and cool conditions are just find with the runners, organizers say. 

The main event just started with serious runners donning not-so-serious costumes for the Halloween event. You don't have to go the full 9 miles, fun runners and 5K enthusiasts also took part.

Runners train months for the event, a staple in the running community for its challenging hill course and unusual 9-mile length. Bret Sholar already had a trophy before crossing the finish line.

He decided to honor his grandfather Russell Pearson who won the Tulsa 5-Mile Marathon in 1929, long before the race became the Tulsa Run.

"He was a great runner," Sholar said. "He inspired me to run. I just thought it would be a good way to honor a man who lived 103 years - he had a great life."

Scott Smith was the first Tulsan to finish this year. 

"It was difficult. I felt worse than I expected to," he said. I wanted to be more competitive in regards to the front of the race, but those guys just took off - so early."

J.D. Stigall hasn't missed the Tulsa Run since it started 38 years ago.

“Just keep moving, that's what I'm doing," Stigall said.

She's seen the race course change slightly over the years and endured everything from ice to heat.

Water main projects on 21st Street between Utica and Peoria Avenues forced the race course to move up two blocks. Runners on the 15K course made right turns onto 19th and cut through the neighborhoods.

The Tulsa Run will celebrate its 39th year next year. It's always the last Saturday in October, so get training!