Solon Spiro arrived in Park City in 1881 at the age of 18 to work for his uncle M. S. Ascheim in his mercantile business. He had graduated from private secondary and business colleges in Germany, so was well-prepared. He worked with his uncle until 1900 when he began buying claims and mines including at the Little Bell, Lucky Bill and Bogan Mines. He sold the Little Bell and Lucky Bill interests to concentrate on the Bogan properties of the King Con mine. As he invested and enlarged the facilities there, it became apparent that the overwhelming problem of water in the underground workings could be solved by a deep drain tunnel.
In spring 1916, Spiro "launched construction of an ambitious tunnel designed to drain the major portion of the company's property and, it was hoped, provide access to new ore bodies." Construction of the Spiro Tunnel began that summer with Jack Keetley, former Pony Express rider and Ontario Drain Tunnel contractor, at the helm. Forty workers advanced the Spiro Tunnel in round-the-clock shifts. The tunnel produced no ore, but allowed underground access to the mining potentials of the surrounding claims.
In 1918 Spiro completed the purchase of the Comstock-California Mine; the King Con now controlled 1400 acres of mining claims. He modernized the mill and pursued lengthening the Spiro Tunnel to also de-water those underground workings. The production of ore continued at the Comstock-California, with profits contributing to the drain tunnel construction costs, even though haulage from the mill high in Park City’s mountains was difficult.
Through all of the acquisition of Comstock-California and the large production facility at the Bogan Shaft, Solon Spiro discovered that the Silver King Coalition was stealing ore underground that belonged to the King Con. He finally won a court judgement against the Silver King Coalition for $900,000 and work continued to complete the Spiro Drain Tunnel. By January 1922 it had reached a depth of more than 15,000 feet but without passing through any substantial ore deposits. Construction costs mounted with the very unfortunate conclusion in 1924, Solon Spiro’s Silver King Consolidated was forced to sell to the Silver King Coalition. Spiro never found the valuable ore in the tunnel that he was seeking but local folklore recounts that short time after acquiring, the Silver King “struck it rich”.
When Park City’s last mine company developed Park City Ski Resort, they conceived the unique idea to transport skiers to the slopes via the Spiro Tunnel. In 1965, the “skier subway” opened. Skiers could board re-purposed mine cars, journey three miles underground to the Thaynes shaft, then ride the hoist (mine elevator) to the surface. The ordeal took 45 minutes. Though popular as a novelty, most skiers rode the train only once before heading back to traditional chairlifts.