The stone came from the Stout Quarry, in the hills (known as hogbacks) just west of town. In addition to the many building projects in Fort Collins from the 1860s on, the stone was used by the Union Pacific Railroad for construction of bridges, stations, and roundhouses on the Oregon Short Line, which ran from Wyoming to Oregon.
Stone was hauled out by wagon four miles to the railroad tracks for delivery to Denver and beyond. The three-block-long Canyon Avenue in downtown Fort Collins was so named because it was the route used to bring the stone into town, which also explains why it runs on a diagonal in relation to the north/south and east/west streets.
The little town of Stout grew out of quarry workers' camp, where it remained until the construction of Horsetooth Reservoir in 1949. Many of the buildings were sold and moved. Others were demolished, and their remains are under the reservoir.
On a separate note: Happy Birthday to my sister! I hope she feels like a Queen today.