The Cold Spring Ranch, among the first ranches established in northern Colorado, began when George Mortimer Pullman acquired 320 acres at the junction of South Golden and Mt. Vernon Roads on September 22, 1860. With one road leading northeast to the Gregory Diggings of today's Gilpin County and the other leading southwest to the Jackson Diggings near today's Idaho Springs, it was quite the strategic spot to put up a way station for travelers! The ranch had the advantage of a very fine cool water spring at the southern end of the junction.

There Pullman built his stage stop which came to be known as the Pullman House. This house was a 1-story log building of rather basic design, constructed of hand-hewn V-notched logs cut from the pineries west of Golden.  It sat upon a pretentious foundation of cut stone, one of the earliest known to exist in the area. It was a perfect place to establish a way station, supply and resting place at an important crossroads to the gold fields beyond. People could stay here, rest and water their oxen and horses, and more.

Pullman came here from Chicago in 1860. There he had recently worked on his invention of a sleeper railcar for public travel, and had come west to the gold rush to make money to realize his dream of making them. Pullman did not make a ton of money on gold milling, but was certainly open to other business ventures, such as operating a freight business and keeping a store in Central City under the name of Lyon, Pullman & Company. Being at a midway point on his constant journeys back and forth between Central City and Denver, this location caught his eye. On September 22, 1860 Pullman traded 5 yoke of cattle and a lumber wagon with John F. Vandevanter, a gold rusher from Sturgis, Michigan, for his half interest in the junction. Spafford C. Field, the brother of Pullman's associate Benjamin Field in Illinois (his partner in inventing the Pullman cars), who had just moved to Colorado, acquired the interest of Vandevanter's partner Robert D. Thompson. Quickly Pullman seized upon the opportunity to make his spread a large operation.

Nearby in the spring of 1859 George Sears had claimed 160 acres of land, which that fall was jumped by James Snow, who built a house upon it. Snow conveyed this land to Field in the fall of 1860 for $400. Also in the spring of 1859 James Orr took a claim of 160 acre, which claim was jumped by downtown Golden merchant George W. Edgecomb in the summer of 1860. That fall he sold that claim to Field for $100. Hill and Sturgis took their own 160-acre claim in the spring of 1859, which then was jumped by Richardson and Patterson in the fall of 1859 and sold by them to Hiram Nye in the spring of 1860, who then sold it the following fall via execution in favor of George Harlow and was bid off by Field who held a Sheriff's deed for the place. In 1861 Pullman claimed 160 acres more, while partner James E. Lyon claimed another 160 acres, and partner J.S. Pimple claimed his own 160 acres. Another partner Morris also claimed 160 acres, and partner Samuel F. Cooper, a fellow miner of Pullman's in Russell Gulch, claimed 160 acres. The whole was assembled together into the expanded 1,600 acre Cold Spring Ranch. On May 20, 1861, the expanded Cold Spring Ranch was officially platted, now a prominent way station ranch.