This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
7/17/2026
Rocky Mountain Steel Mills (RMSM) this month marked the start of operations at its new long rail mill in Pueblo, Colorado, by delivering the first stick of rail produced at the facility to Union Pacific Railroad.
The new, $1.2 billion facility produces 328-foot lengths of rail. The long rail has significant efficiency gains, as it requires 80% fewer welds than standard 80-foot rails, improving track safety and reliability, UP officials said in a press release. The facility is powered by a dedicated 1,800-acre solar farm, making it the world’s largest solar-powered steel mill, they said.
“This mill is an essential part of America’s steel transportation infrastructure," said Doug Matthews, CEO of Orion Steel, the parent company of RMSM. "Its continued existence shows that our nation offers railroads large and small the very best product, made by the very best steelmakers in the world."
In April, UP and RMSM, under new ownership and management, signed a seven-year contract for the domestic production of steel rails. UP has been using RMSM rail since the early 1890s; the railroad purchased the first stick of rail produced by the original Pueblo rail mill in 1882.
To mark the official start of operations, UP CEO Jim Vena toured the facility and met with mills employees.
“Union Pacific and Rocky Mountain Steel Mills have a proud history of supporting American manufacturing, jobs and communities," said Vena. "This renewed partnership will help strengthen our country's supply chain and demonstrates the importance of reliable rail transportation in keeping our economy moving.”
RMSM is the only remaining dedicated rail production facility in the United States and one of the largest producers of steel products in North America, mill officials said. Steel made for UP and all RMSM customers is produced by members of the United Steelworkers.