Train Mountain Railroad, Railroad theme park in Klamath County, United States.

Train Mountain Railroad is a theme park in Klamath County featuring miniature train routes that wind through the forested landscape. Visitors ride in small trains along elaborate track systems set at high elevation in the region.

Train Mountain was founded by Quentin Breen, whose dream of building the railroad was featured on Oregon Public Broadcasting in 2005. In 2004 Guinness World Records recognized it as the longest miniature hobby railroad, with 69,900 feet of mainline track and 133,250 feet total. The Triennials began in 2000, and the 25th anniversary was celebrated in 2012.

Since 2000, Train Mountain has held a Triennial meet every three years, skipped only in 2021 and moved to 2022 because of the COVID-19 pandemic. On the final Saturday, all trains gather for the Big Toot and sound their whistles for one minute. Participants have come from Australia, Switzerland, Canada, Germany, the UK and the US.

Bring appropriate clothing for the high elevation and changing weather conditions, as the grounds are exposed to the elements. Tour lengths vary, so plan your timing based on how long you want to spend on the rides.

The museum holds Southern Pacific MW206, a 100-short-ton rotary snowplow built by ALCo (Cooke) in November 1923 and moved here on November 16, 2008; it once cleared tracks between Klamath Falls and Eugene. In August 2024 the site received Weyerhaeuser Timber Company #101, a Baldwin DS-4-4-750 built in May 1950 as one of two demonstrator units, and Train Mountain's first full-size display locomotive.