DENVER (KDVR) — Have you ever wanted to see the Pony Express operating as it once did in 1860? There's a chance to do just that thanks to the National Pony Express Association.

On Wednesday, July 11, the organization launched its annual re-ride in Sacramento, California, and if all goes well, by 7:30 p.m. on July 21, the mail carried by the riders will be in St. Joseph, Missouri.

What was the Pony Express, and why are there re-rides?

The Pony Express Trail crosses 1,966 miles in eight states, and at one point in American history, the Pony Express was the fastest way to deliver mail. The Pony Express began operations on June 16, 1860, according to the National Pony Express Association, and about 10 weeks later, Congress authorized a transcontinental telegraph line from the Missouri River to the Pacific Coast.

Until that line was completed, riders with the Pony Express carried letters, newspapers and other mail from St. Joseph to Sacramento. But on Oct. 26, 1861, the Pony Express was officially done, with the last letters carried on the trail recorded in November 1861.

The National Pony Express Association, which is run entirely by volunteers, said that the annual re-rides of the Pony Express Trail began in the mid-1960s with a group that started doing reenactments of the express. In 1977, the Association was formed and the first fully Pony Express Trail re-ride was recorded in 1980.

The nonprofit says on its website that each annual ride takes about 650 riders to complete, with the riders traveling 24/7.

And yes, the riders do still carry mail: A "mochila" is placed over each rider's saddle with four pouches that carry upward of 1,200 pieces of mail before it is transferred to the United States Postal Service. Interested individuals can even send a piece of mail to be carried on the trail. However, the deadline for this year has passed.

When will the Pony Express riders be in Colorado?

The Pony Express riders are expected to reach the Colorado/Nebraska state line at about 2:30 a.m. on Thursday, June 19. The border crossing will be near the fairgrounds at Chappell, Nebraska.

The express is scheduled to reach Ovid, Colorado, at about 3:30 a.m., and the Colorado Welcome Center at Interstate 76 and Highway 385 at about 4:15 a.m.

Colorado's section of the trail is about 26 miles long, starting at the Nebraska state line east of Julesburg, traveling westward on the South Platte River, then north along Lodgepole Creek before it heads back into Nebraska.

Riders will leave Colorado at about 6 a.m. on Thursday at the Colorado/Nebraska state line, about a mile south of Big Springs, Nebraska.