A big piece of Americana passed through eastern Pennsylvania on Thursday, as part of a coast-to-coast tour in celebration of America’s 250th birthday Saturday.

People all across America have been getting a glimpse of Union Pacific’s Big Boy No. 4014, known as the world’s largest operating steam locomotive, during its tour that began April 10 in Sacramento, California.

Admirers of the historic locomotive braved the intense heat Thursday afternoon to see with their own eyes and hear its whistle blow at the Reading & Northern Outer Station in the Reading area of Berks County.

Several visitors were treated for heat-related illness during Extreme Heat Warning conditions.

“It’s a once-in-a-lifetime experience, because you will never really see these operating,” said Chris Weiss, of Emmaus. “It’s the only one left operating in the United States.”

As it tours the country, Big Boy No. 4014 will be joined by couple of historic passenger cars and the No. 1616 Abraham Lincoln and No. 1776-America250 from Union Pacific’s Heritage Fleet.

For the Berks stop Thursday, Reading Blue Mountain & Northern also operated a special excursion train that was powered by RBMN diesels No. 1776 and No. 2026.

They arrived shortly before No. 4014 pulled into the Reading & Northern Outer Station in Muhlenberg Township, leading a 25-car train with more than 1,000 passengers.

Matt Reier drove up from North Carolina to see the Big Boy.

“I had to make the drive up to see it,” said Reier. “I don’t think I’ll get another chance.”

The Big Boy No. 4014 is 133 feet in length and weighs 1.2 million pounds. During the 20th century, there were 25 Big Boy locomotives commissioned by Union Pacific.

“It’s an awesome sight,” said Tricia DeFrancisco, of Exeter.

The United States has more than a love affair with locomotives — the railroads that crisscrossed the nation literally helped build America.

Before locomotives existed, traveling cross-country wasn’t easy. It took months and was only achieved by wagon or ship. But in 1862, President Abraham Lincoln signed the Pacific Railway Act, which helped keep the Union together during the Civil War. On May 10, 1869, the Central Pacific and Union Pacific track met at Promontory Summit in Utah, joining our two coasts.

The first Big Boy entered service in 1941 and operated between Ogden, Utah, and Cheyenne, Wyoming, moving equipment in support of World War II.

In December 1961, Big Boy No. 4014 retired after traveling 1,031,205 miles.

In 2013, Union Pacific reacquired the locomotive from a train museum in Pomona, California, and relocated it in Cheyenne for a huge restoration project. It ultimately returned to service in May of 2019 to celebrate the 150th anniversary completion of the Transcontinental Railroad.

It is one of eight remaining Big Boys in existence. The other seven are on display in St. Louis, Missouri; Dallas, Texas; Omaha, Nebraska; Denver, Colorado; Scranton, Pennsylvania; Green Bay, Wisconsin; and Cheyenne, Wyoming.

After its Reading visit, the Big Boy No. 4014 continued its tour with a swing through Pottstown and a stop with no public access in King of Prussia on Friday, before ultimately arriving in Philadelphia for a massive Fourth of July celebration.

Check out the pictures below to see scenes from the Big Boy No. 4014 stop in Berks County.

Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.The Union Pacific Big Boy No. 4014 approaches the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.A boy waves as the Union Pacific Big Boy No. 4014 pulls into the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Matt Reier, of North Carolina, gives the thumbs-up as he sports a patriotic train t-shirt as he waits for the Union Pacific Big Boy No. 4014 to stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People hag on fences as they try to get a glimpse of the Union Pacific Big Boy No. 4014 at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Wyatt Brightbill, 4, of Perry County, protects his ears as he waits for the whistle to blow as the Union Pacific Big Boy No. 4014 makes a stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People pose for photos in front of the Union Pacific Big Boy No. 4014 as it stops at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Union Pacific Big Boy No. 4014 begins to pull away after stopping at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Union Pacific Big Boy No. 4014 makes a short stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People braved the intense heat to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Chris Weiss, of Emmaus, gets his camera ready before the Union Pacific Big Boy No. 4014 makes a short stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Families pose for photos in front of the Union Pacific Big Boy No. 4014 as it stops at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Ed Dickens, train engineer and senior manager of Union Pacific Railroad’s heritage operations, look on from the cab of Big Boy No. 4014, as it stops at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People gather to see the Union Pacific Big Boy No. 4014 stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People wave at the Reading and Northern No. 2026 and No. 1776 locomotives as they pull into the Reading & Northern Outer Station before the Big Boy No. 4014 on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Jimmy Thompson, Lead Boilermaker Steam Crew with Union Pacific 4014, looks on as the Union Pacific Big Boy No. 4014 stops at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Union Pacific Big Boy No. 4014 makes a short stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People wave as the Union Pacific Big Boy No. 4014 begins to depart from the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Union Pacific Big Boy No. 4014 begins to pull away after stopping at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.People line the tracks to see the Union Pacific Big Boy No. 4014 as it departs the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com Union Pacific Big Boy No. 4014 locomotive visits Reading, PA.Union Pacific Big Boy No. 4014 continues its tour after a short stop at the Reading & Northern Outer Station on Thursday, July 2, 2026, in Reading, during its nationwide tour commemorating America’s 250th anniversary.Saed Hindash | For lehighvalleylive.com