For the first time in 42 years, one of NASCAR's national series returns to a dirt track.
During two practice sessions, there were spinouts, there was passing, there were new tires ... and there was mud. Lots of it.
See below for some of the best images from the first day at the track, and continue to check back as we upload more photos.
See the difference? Racing on dirt requires a completely different type of grooved tire, as seen on the left.
Teams had a fresh fleet of new tires for practice at Eldora Speedway. Here, Scott Bloomquist's team gets the rubber ready.
Expect things to get dirty at Eldora, much like the grille of Dave Blaney's No. 19 Ford. Blaney is one of two NASCAR Sprint Cup Series regulars racing for a spot in the field (Ryan Newman is the other). Blaney has a history on dirt and posted the second-fastest time of the opening practice, just ahead of son Ryan Blaney, who was third.
Jeb Burton kicks up dirt during one of his first laps around the half-mile, 24-degree banked dirt track in Ohio.
In addition to spraying dirt, John Wes Townley took a spin during the opening two-hour practice session. He wasn't alone, either, as multiple drivers spun out while trying to get their bearings.
NASCAR Camping World Truck Series vehicles are equipped a bit differently for Wednesday night's The CarCash Mudsummer Classic presented by CNBC Prime's The Profit.
Ty Dillon, pictured, and brother Austin Dillon both have raced on dirt before. They were among the first drivers out onto the track for the first practice, and then they went up in the stands to get a high-level view of what other trucks were trying while adjustments were being made on their respective machines.
Austin Dillon posted the fastest time during the second practice session Tuesday, sending up long plumes of dirt in his No. 39 Chevrolet.
Like a proud father, Tony Stewart took in the action Tuesday. Stewart owns Eldora Speedway and was instrumental in helping to bring the sport's sanctioning body back to dirt.
Much like you might see ringers at a road course, there are some dirt ringers at Eldora. One of them is Tracy Hines, who posted the fifth-fastest time of the second practice session in his No. 13 Toyota.
Fans came early and stayed late for Tuesday's practice sessions, so you know Wednesday's qualifying heats and actual race will be well-attended.
This is what the fans came to see: dirt. Or, mud in some cases. The track was slicker for the second practice session, causing the speeds to go down.