Freight haulage became a very important part of the WCF&N operation. It all began on 10 August 1900, when a carload of brick was hauled to a construction site in Waterloo from a brickyard located in Cedar Falls. This was done with an interurban unit pulling a flat car. The WCF&N differed greatly on the issue of freight haulage from other electric lines in operation in the nation. Management realized that the steam lines needed interchange arrangements. Seeing this opportunity, the company bought nine box cars and four flatcars to haul freight. These trains were pulled by interurban cars and operated between midnight and early morning. Because the interurbans were too small to continue operating in this way practically, the company built an electric freight engine in 1900 and another in 1901. This second locomotive was used to carry coal to the Normal School one car at a time.
Also, in 1901, at 6th and Mulberry Streets, an interchange was constructed with the CGW, and it became the main interchange for steam-powered freight service to Denver. A site was purchased in 1902 on the Denver line north of the city for a carhouse because the Dane Street facility was the only one that serviced both steam and electric locomotives. This new facility contained a conventional roundhouse and turntable. Both this new facility and the first segment of the freight belt line opened in 1903. This segment went from the shop to Highland Yard, where there was an interchange with the CGW. The complete extension of the belt line went from Newell Avenue to Belt Junction. Residents living on Mulberry Street did not want freight service trains passing their homes from the 6th Street interchange, so they petitioned the Waterloo City Council. The Council decided in favor of the residents and ordered that the original interchange be removed.
In 1908, access was gained to the growing Westfield industrial area by a line built along Westfield Avenue. This industrial area contained the Waterloo Gasoline Engine Company (later called John Deere) and the William Galloway Company. Waterloo’s population had grown to around 35,000 people during the first twenty years of the twentieth century. The city contained more than one hundred factories and the WCF&N operated a belt line that connected most of these factories with their interurban lines and the lines of the steam railroads. Cedar Falls also grew to about 10,000 people and the WCF&N operated a loop that connected the business section with the Iowa State Teachers College. Located in the center of the business district was the terminal depot through which all of the interurban and local traffic passed. The expansion into freight service helped the WCF&N to become more profitable and expand.
In 1910, after the construction of the electric line from Denver to Waverly, management of the WCF&N was encouraged by executives of the Chicago and Northwestern and the Chicago, Milwaukee and St. Paul railroads to extend a line to Cedar Rapids. The company did some thorough investigating and decided to extend the line. Construction began in July 1912. In November, when construction ended because of winter, the tracks reached beyond Gilbertville and were within four miles of La Porte City. Construction began again in the spring of 1913. The tracks had reached Brandon by September and Urbana by December. In June of 1914 service opened in Center Point and reached to Cedar Rapids by August. Soon after electric wires were also in place. When service reached Cedar Rapids a connection was made with the Cedar Rapids and Marion City Railway. Tracks of the Cedar Rapids & Iowa City Railway (Crandic) were then used to gain access to downtown Cedar Rapids. The WCF&N then built a yard and depot on the north end of Cedar Rapids. This facility was used mostly for freight.