Mason City's railroad development began in 1869 when the McGregor & Missouri River Rwy laid track from Nora Springs to Clear Lake as part of a link between Chicago and South Dakota, and in 1870-71 when the Mason City & Minnesota and the Iowa Central RR began establishing a north-south route to move coal from the Fort Dodge area. By the early 1900's, these and other regional short lines had merged into five major rail lines that served Mason City through most of the steam era. A sixth steam-era railway, the local Mason City & Clear Lake RR, began as an electric rail service in 1897 and survives as the Iowa Traction RR, connecting businesses, passengers, and rail transfer services between the major regional lines. Rail service supported major industries including cement, bricks, tile, fertilizer, sugar, dairy, livestock, and meat, while many other businesses such as fruit, groceries, lumber, coal, kerosene, oil, fur and hides, furniture, grain, milling, and feed also depended on the railroads to move products into and out of Mason City. Passenger service expanded rapidly across the region, and in 1915 the M&StL RR alone served nearly 2 million passengers. In the mid 1930s, diesel locomotives began to be introduced and operated alongside steam for nearly 25 years before steam was phased out in the late 1950s; after that, steam power largely disappeared except on remote lines, tourist excursions, and in museums as diesel became dominant.