From both independent research and from my over 30 years in the field, I believe this example of the "Flathead Camp on the Jocko River" to be the one of only two extant prints of this image to be done by Curtis in the Double Border Silver Print format. Given that Silver Prints by Edward Curtis are rare to begin with, this example is extremely rare even by the standards for a Curtis Silver Print.
Adding to the rarity of this work is the fact that Curtis, unlike most photographers of his era, created a larger body of platinum prints than of silver prints. So while platinum prints comprise well under one half of one percent of existing Curtis prints, the Curtis silver print exists in even fewer number than the platinum prints by a significant number.
The Silver prints were made on a paper sensitized with an emulsion silver salts; usually silver bromide, iodide, or chloride. After developing, they were carefully toned to bring out and enhance the subtle tones of Curtis’ prints and to make those prints more permanent. Frequently, they were double printed to give a border effect.
Further, this is an unusually large example of a Curtis silver print, measuring approximately 9 5/8 x 11 1/4 inches. Curtis' silver prints normally range in size from 4.5 x 6 inches to 6 x 8 inches in size.
The print is accompanied the original Curtis Studio description label. This unique work has been in the same family for over 90 years and has never appeared on the market before.