One of the great things about history is that we never know what will turn up next. The portrait shown here - one of only two known photographs of Captain John Williams Gunnison-is a case in point.

Gunnison led a well-known government survey expedition through south and central Colorado in 1853 to locate a railroad route linking eastern cities with California. The party deemed the so-called Central Route unfeasible because it crossed such insurmountable obstacles as the Sangre de Cristo Mountains and the Black Canyon. Still, the survey's geological and topographical observations informed many changes that followed the 1858 discovery of Colorado gold. These contributions were largely overshadowed by the expedition's tragic end on October 25, 1853, when eight members, including Gunnison, were killed in Utah.

This rare portrait is a positive image on glass. The process used to make it is related to the wet - collodion negative process used throughout Colorado's territorial years and well into early statehood. The first description of either process dates from 1851, but the positive process-generally known as "ambrotype"-was not patented until 1854. This poses a puzzle for curators and historians: does the portrait represent an early, experimental use of the process, or is it an ambrotype copy of a daguerreotype that has since been lost? Research will continue on this question.

Gunnison's portrait was given to his brother after the explorer's death. It passed down through the family for 144 years, until a California man who recognized the picture's historical meaning saw it at a 1997 estate sale, and bought it. Later, he offered the portrait to the Colorado Historical Society through Brian Levine, the proprietor of Mount Gothic Tomes and Reliquary in Crested Butte. The Society looks forward to exhibiting and publishing the original, which has not been displayed in public since the expedition's fiftieth anniversary celebration in Gunnison.

Because History Colorado, as a state agency, has limited acquisition money, we turned to the Colorado Historical Foundation for help. This non-governmental charitable foundation created the Hart Library Acquisition Fund to raise private funds which could be used to acquire rare and exceptionally significant historical items. The Foundation made an initial gift of $10,000 to the Fund in honor of the Janis and William Falkenberg family, who have been long-time supporters of the Hart Library. This gift made the purchase of the Gunnison ambrotype possible.

History Colorado encourages others who would like to support the acquisition of special items for the Stephen H. Hart Library & Research Center to contribute to the Foundation's Library Acquisition Fund.