Dierks Bentley said he knew this year’s “Miles & Music For Kids” event was bigger the second he pulled up to the Harley dealership yesterday (Oct. 17).

“I got my Flip camera out and I was filming the bikes as we drove up here. All those bikes!” Dierks told Country Weekly.

Dierks’ event has drawn about 700 bikers through Middle Tennessee in years past. But organizers estimated there were between 1,000 and 1,500 bikers for this year, the fifth in Nashville, with final numbers expected later today.

“More and more bikes every year. The support from the community is always a surprise. You never know what to expect in this business. I’m really pleasantly surprised at this turnout,” Dierks said.

The ride culminated with a five-hour outdoor concert with Dierks, Luke Bryan, Heidi Newfield and bunches of others.

Dierks’ rides—now in several cities throughout the U.S.—have raised more than $1.3 million for children’s hospitals.