The buildings are associated with the settlement of Boulder County.  The buildings are the product of the local sandstone industry.

Longmont contractor Mark Boyd built the depot in 1885 utilizing native Lyons sandstone.  Used first by the narrow gauge Denver, Utah and Pacific Railroad, the depot served passengers and freight until declining traffic brought its closure in the 1940s. 

Completed over Culebra Creek on the western edge of San Luis in 1911, this segmental, reinforced concrete open spandrel arch is one of the earliest unaltered bridges of this type in Colorado.

Constructed in 1906, the house is an example of an ornamental concrete block residence.  Its Queen Anne detailing is an unusual expression for concrete block construction and for Costilla County.

Consisting of two 18-foot spans, the steel multiplate arch culvert is faced with local volcanic fieldstone. 

Established in 1851, San Luis is the oldest continuously inhabited town in Colorado.

The 1911 power plant is located along the St. Vrain River just northeast of the town of Lyons.  

Built in 1894, the church is one of the oldest unaltered buildings in Lyons. 

The house is a well preserved example of wood frame miner housing.  

With its pressed tin siding, cornice treatment and window trim intact, the building is an excellent surviving example of the late 19th century vernacular commercial design once commonly found in small towns.