When Guinness recognized Train Mountain in 2004, the facility already had 25 miles of mainline track plus additional yards, sidings, and spurs. Since then, approximately 10 more miles have been added, creating a network so extensive that the longest tours still cannot cover it all. The track layout includes multiple loops, passing sidings, and roundabouts that allow dozens of trains to operate simultaneously without conflict. A computer-controlled Central Train Control system manages switching and signals, bringing sophisticated railroad operations to miniature scale. From satellite imagery, the track network appears as thin lines etched through the forest, betraying little of the engineering complexity required to maintain grades and curves suitable for heavy miniature locomotives.

Every three years since 2000, Train Mountain hosts the Triennial, an international gathering that draws train enthusiasts from Australia, Switzerland, Canada, Germany, the United Kingdom, and across North America. The 2018 event attracted trains totaling more than 10,000 feet in length. The 2022 Triennial saw approximately 888 participants arrive with their locomotives and rolling stock, a slight decline from previous years but with even more trains making the journey. The celebration culminates in the Big Toot: on the final Saturday, every assembled train blows its whistle for one full minute, filling the Oregon forest with a cacophony of steam and sound that echoes across the high desert. Seven additional train meets throughout the year keep the tracks humming with activity.

Alongside the miniature marvels, Train Mountain maintains a museum of full-size railroad equipment that connects the hobby to its industrial ancestry. The collection's crown jewel is Southern Pacific MW206, a rotary snowplow built by ALCo in November 1923. Originally steam-powered, later converted to diesel-electric, this machine once cleared snow from the tracks between Klamath Falls and Eugene. It arrived at Train Mountain in November 2008. In August 2024, the museum acquired Weyerhaeuser Timber Company 101, a Baldwin DS-4-4-750 diesel locomotive built in May 1950. This engine served the Oregon, California and Eastern Railway until 1990, making it Train Mountain's first full-size display locomotive and a tangible link between the timber railroads of the past and the model railroads of today.

The serious practitioners of live steam modeling congregate at Train Mountain because the layout accommodates locomotives that would overwhelm smaller club tracks. The 7.5-inch gauge supports both 1.5-inch scale (approximately 1/8 actual size) and 2.5-inch scale (approximately 1/5 actual size) equipment. Some of the larger steam locomotives, fully loaded with water and fuel, weigh over 2,000 pounds. These are precision machines, their boilers generating real steam pressure, their valve gear replicating the mechanics of full-size locomotives in exacting detail. Oregon Public Broadcasting featured Train Mountain on Oregon Field Guide in 2005 and again in 2017, introducing the wider world to this community of engineers, machinists, and dreamers who build and operate their own railroads.

Train Mountain operates as a club and museum rather than an amusement park, but visitors can experience the railroad through guided tours ranging from 30 minutes to eight hours. Even the longest excursions cannot traverse the entire network. The adjacent Klamath and Western Railroad, a separate nonprofit organization, offers free public rides on Saturdays from Memorial Day through Labor Day. Originally founded as the Over The Hill Live Steamers, this group predates Train Mountain itself and maintains its own collection of antique railroad artifacts, including a train order semaphore signal from the Southern Pacific station in Junction City, Oregon. Together, these organizations preserve not just equipment but the culture and craft of railroading in miniature.