resolutions from lowest to highest:
2. Alfred Edward Mathews (1831-1874). Black Hawk, Looking Up Gregory and Chase's Gulches. Tinted lithograph, Plate 7. Mathews, A.E. Pencil Sketches of Colorado. New York: The Author, 1866. St. Louis Mercantile Library at the University of Missouri - St. Louis.
"The sketch was made from the heights immediately east of the town, looking up Gregory Gulch. On the right is Chase's Gulch. The first hill on the left of Gregory Gulch is Bob Tail Hill; on this hill the shaft houses of Mr. Sensenderfer's mill, the Barstow Mining Company, and the Black Hawk Company are seen. The next hill is Gregory Hill; on this hill the Narragansett Gold Mining Company's Works are seen; at the foot of the hill a portion of the Black Hawk Company's Works are represented. The third hill of this range is Mammoth Hill; here are seen the Gold Rock Mining Company's Works' and at the foot of this hill a portion of Mountain City can be seen; while a little to the right a glimpse of Central City is had. The fourth hill of this range is Quartz Hill, and on the right is Nevada; next to Quartz Hill, and just beyond Nevada is Bald Mountain, and in the distance some peaks of the Snowy Range are seen."