The remaining mountain route , about long , winds between altitudes of 7,000 and over 9,000 feet , from the townsite of Eldora , Colorado , past Nederland , on north through Sugar Loaf and , ultimately , Ward . The line winds past several local historically prominent mines , including the Blue Bird Mine and a few miles from the Caribou Mine in the then-bustling ( now ghost - ) town of Caribou . The main line originated in Boulder , Colorado , coming up Fourmile Canyon through the mining communities of Salina , Colorado and Crisman , Colorado . It was connected via a three-rail track shared with railroads to Denver , Colorado
Fourmile Canyon
Fourmile Canyon
Switzerland Trail