It's an annual event that attracts thousands of people, many from outside the United States, with millions of dollars at stake.

On Thursday, Sept. 20, an estimated 40,000 people will enter the Delaware County Fairgrounds for the 2018 Little Brown Jug harness race for 3-year-old standardbred horses.

It's an event with international appeal, said Brown Jug race secretary Tom Wright.

One year, he said, volunteers checked license plates in fairgrounds parking lots and discovered more than a third of those attending the Little Brown Jug were from Canada.

"We have tour groups from New Zealand, Australia, France -- all over," he said.

Harness racing is popular in Australia and New Zealand, he said, and harness racing for trotters is popular in France.

As many as 10 tour groups bring international visitors to the race each year, he said.

"In the past 12 months, I've talked to dozens of people from outside the country," he said.

On race day, a field of horses competes for $1.2 million in prize money.

Depending on the number of entries and whether the race has two or three divisions, the horse that wins the Jug likely will earn a purse between $300,000 to $350,000, Wright said.

Another attraction is the ability to bet on the races. More than than $2 million was wagered at the 2017 Brown Jug.

The traditional way to bet at a harness race is at a pari- mutuel booth, and the fairgrounds will have more than 100 in operation -- in both buildings and tents -- manned by about 120 people, Wright said.

In recent years, the fairgrounds has added self-betting terminals, and Wright said there will be about 35 around the fairgrounds.

Accepting only cash, the terminals direct the user through the betting process, with options for the type of bet, amount to be bet and horse selection. The terminal will print a ticket the holder can use for more bets, or redeem at a pari-mutuel booth.

"The machines are easy to use and are popular with many patrons," Wright said.

Race fans don't even have to be in Delaware to bet on the Brown Jug, he said.

Wagers can be made at off-track betting parlors at simulcast locations in the United States and other countries, he said. The parlors are at commercial horse racing tracks that operate on a seasonal basis.

"I don't know how many different countries" have such betting parlors, Wright said, adding that the amount bet at those locations might exceed the total wagered at the fairgrounds.

Beer and wine sales take place daily during the fair at the racetrack and motor-sports area.

On Wednesday and Thursday during fair week -- when the Jugette race for fillies and Brown Jug are held, respectively -- liquor is available at four spots around the race track.

A Brown Jug tradition is bringing your own alcohol when watching the races from the track's backstretch, which has no bleachers.

Brown Jug publicity spokesman Jay Wolf said, "All we ask is that the patrons be responsible, be respectful of each other and be safe. We do not allow glass -- plastic and cans only."

Another Brown Jug tradition is bringing your own seating for the large section of track that has no bleachers.

Wright said some race fans bring wagons covered with seats or hay bales for seating.

Others keep folding chairs locked to the fence surrounding the racetrack to reserve a spot.

Races are held daily during the fair, and Wright estimated more than 500 horses are on the track during the week.

A large number of race-related activities also are scheduled, including autograph sessions, meet and greets with racing personalities and horses, a speakers series, a prayer breakfast and seminars held by the Ohio Harness Horsemen's Association.

Before the 2018 fair opened, Wright said, "Everyone's getting excited and prepared for the Little Brown Jug. ... For me, the excitement is seeing all the people who come back every year to help us. It's a lot of fun and a family reunion in that regard. Once the excitement gets into you, you want to give it all you've got."