DENVER (KDVR) – “Big Boy,” one of the world’s largest trains, is taking off on Wednesday and plans to stop in 10 states while on tour.

The history of Big Boy started with 25 trains, each of which were 132 feet long and 1.2 million pounds. The company said all are now out of service or on display, except for one: Big Boy No. 4014.

It originally ran in 1941 and retired after 20 years and over 1 million miles. However, after a lengthy restoration, the Union Pacific Railroad says the train is now the world’s largest operating steam locomotive and is ready to hit the rails again.

Union Pacific Railroad announced the train’s second-ever tour: The “Heartland of America Tour.”

The massive train will depart from Cheyenne, Wyoming, Wednesday before making more than 40 stops across nine other states: Arkansas, Colorado, Illinois, Iowa, Kansas, Missouri, Nebraska, Oklahoma and Texas.

The tour runs for eight weeks. You can see all the scheduled stops and viewing opportunities at the Union Pacific Railroad’s website. Some of them are longer display visits – planned for Rochelle, Illinois; Houston; and Fort Worth, Texas – and dozens more are short “whistle stops” or viewing opportunities. They’ve also set up a live tracker so you can watch it move across the country on tour.

Seven other Big Boys are out of commission but on display. You can visit them in Cheyenne, Wyoming; Dallas; Denver; Green Bay, Wisconsin; Omaha, Nebraska; Scranton, Pennsylvania; and St. Louis.