Roughly includes the south side of Spruce St. from 10th St. to 16th St., Pearl St. from 9th St. to 16th St., and the north side of Walnut St. from Broadway to 9th St. Also includes the Post Office at 14th and Walnut and the Hotel Boulderado at 13th and Spruce.

Constructed in a rugged mountain setting over Boulder Creek in 1953, the three span bridge runs for 100 feet, with the main 48-foot span flanked by shorter approach spans.  

The circa 1901 building was constructed as part of Charles Caryl’s ambitious development plan for his Gold Extraction Mining and Supply Company, which he founded in 1897.  The primarily stone two-story building is topped with a steeply pitched metal covered hipped roof.

This well-built 1900 rural schoolhouse, of granite with sandstone trim, reflects the prosperity of the town at that time. 

This ca. 1875-1876 wood frame rural schoolhouse is one of the oldest school buildings in the county.

Built ca. 1902-1908, the wood frame church is part of a small cluster of buildings remaining from Salina’s late 19th and early 20th century mining boom.  The original portion of the building has a front gabled roof, and a bell tower entry extends from the façade.

Located on just under two acres of land donated by early settler Jerome Gould, burials at the cemetery approach a total of 300.  The original by-laws of the Niwot Cemetery Association were adopted on January 4, 1884. 

The Rocky Mountain Mammoth Mine is significant for its association with the mining industry in the mountains of Boulder County.  As a telluride gold ore producing mine, the Rocky Mountain Mammoth contributed to a major mining revival experienced in the Magnolia Mining district and elsewhere in Boulder County in the late 1890s and early 1900s.

The 1901 Cardinal Mill is significant for engineering and industry as an outstanding example of a concentration facility as defined in the Mining Industry in Colorado Multiple Property Listing, and Amendment to Metal Mining and Tourist-Era Resources of Boulder County Multiple Property Documentation Form (MPDF).  The mill was important to western Boulder County, contributing to a highly productive tungsten ore operation until 1942. 

The trail to the summit of Longs Peak reflects the principles of National Park Service Naturalistic Design from the 1920s through the 1940s.  Active tourist use of the trail began in 1873 and continues up until the present day with hundreds of personal accounts repeatedly expressing exhilaration over the scenery and exhaustion from this high-altitude effort.  Initially lodge owners maintained the trail and climbers hired local guides to assist in their mountain ascent.  Between 1900 and 1906, Enos Mills forged his skills as a public speaker and naturalist while guiding visito