The mail stage in Boulder Canyon in the late 1860’s
The first prospectors arrived in the area that is now Boulder late in 1858. The town they established was first called Boulder City but then shortened to Boulder by the time the Post Office was established on April 22, 1859. This area was part of Nebraska Territory until the formation of Colorado Territory on February 28, 1861.
One of the three reported examples from Colorado while Nebraska Territory
30 January 1861 Boulder, Nebraska Territory to Illinois