Humboldt Street Historic District, Historic district in Denver, Colorado.

Humboldt Street Historic District, also called Humboldt Island, runs along Humboldt Street between East Tenth and Twelfth Streets, west of Cheesman Park in Denver. Its 25 houses, built between 1895 and 1920, were designed by firms such as Willison and Fallis, Marean and Norton and the Barressen Brothers in Renaissance Revival, Georgian Revival, Colonial Revival and simple Foursquare styles.

Humboldt Street was the first residential district designated a historic district by the Denver Landmark Preservation Commission, in 1972, and is listed on the National Register of Historic Places. Its 25 houses were built between 1895 and 1920. After Frederick G. Bonfils' mansion was torn down for a fifteen-story apartment house, Denver passed an ordinance protecting Cheesman Park's mountain view from high-rises.

Humboldt Island takes its nickname from the tight block of Humboldt Street, where the Bonfils and Tammen families of The Denver Post kept homes; Tammen's Tuscan villa stood at 1061 Humboldt. The street names and house numbers still let visitors trace these newspaper and mining families.

The district lies west of Cheesman Park and is easy to explore on foot. Wear good walking shoes and plan to visit during daylight hours, as you will be walking through an active residential neighborhood.

The Stoiber-Reed-Humphreys Mansion, the district's showiest house, was built for mining millionaires the Stoibers in the Renaissance Revival style. Verner Zevola Reed later owned it, and Josephine Trott, a Denver piano prodigy, also lived on Humboldt Street. The district's 25 houses were designed by firms including Willison and Fallis, Marean and Norton, and the Barressen Brothers.