Views of the entrance to Boulder Canyon, looking north from Flagstaff Mountain. Visible are Yount Flour Mill, house on Douty Placer, Atlas and Delano Mill, Boulder-Colorado Sanitarium, Farmers and Silver Lake ditches.  Between 1883 and 1911.  Photo Courtesy of Carnegie Branch Library for Local History, Boulder Historical Society Collection.

2008 photo by John McKenzie.1800s:Local call number at Carnegie Branch Library for Local History: BHS 208-2-44PHOTO #3