John Zimmerman and his family had a huge impact upon the early history of the Poudre Canyon. John was known for his intelligence, persistence, indomitable courage and perseverance in proving to the world that gold did exist in Poudre Canyon. Born in the Alps of Switzerland, he was comfortable reading the rock formations and signs of probable locations of gold ore.Typical of Gold Rush prospectors, John and his brother Michael began digging around Cameron Pass, following rumors of gold in that area. Soon they moved on down the Poudre Canyon to just above Rustic and approximately 1 mile above Archer’s Poudre River Resort. They staked their claim and called it the Elkhorn Mine. The high cost of transporting the ore to a reducing works ate up the profits of their labor. Since John had worked in an ore stamp mill in Nevada, he was comfortable with the idea of building a Stamp Mill on the Poudre River. He named the area of growing population, Poudre City.
The Mill consisted of a five-stamp battery, a roasting furnace, four amalgamators, one 2.5 horsepower steam boiler with its furnace and steam gauge and a mill race that turned a 12-foot high breast wheel with seven-foot buckets. What a sight it must have been. There were 5 buildings in all that were a part of the operation. Zimmerman fired up the Mill in October of 1890. He processed the Elkhorn ore and took the retorts to Fort Collins. The estimates of value fueled the rumor that Larimer County was destined to be the richest mining county It was later determined that the value was tremendously over estimated, but not until after the rush of would-be miners had dotted the mountainside with holes, in search of gold.
The operation of the mill was short lived. In June of 1891 the earthen dam at Chambers Lake burst. John heard the roar of the oncoming wall of water and rushed by horseback to Poudre City to warn the residents of the danger. All 13 people living at the Mill site and Poudre City were evacuated. The Mill was lifted off it’s foundation and the walls collapsed leaving only the stone chimney as witness to what had been. John filed a lawsuit against the Larimer County Ditch Company for his $7,500 loss. The court awarded him $1,750 in damages. A Historical Marker has been erected at the site. Park your vehicle in the Poudre Canyon Chapel parking lot and take the short trail down to the former site of “Old Poudre City” and Zimmerman Stamp Mill.
Example of the Stamp Mill used by John Zimmerman. Ore fed under iron 'Stamps' from rear hopper. Steam, water or electric belt-driven power turned wheel which revolved cams. This Stamp mill was used to crush gold ore at the Fortuna Mine near Nevada City.