This is the more uncommon Ra four pen, 5 inch blade which dates from 1870 to 1890. There is wear due to use an age. Green River Works 5-inch blade Buffalo Skinner knife, often with a 4-pin handle is a classic piece of American cutlery from the fur trade era, known for its high-carbon steel that holds a sharp edge, used by mountain men. Key Characteristics: Maker: John Russell & Co. Green River Works (America's oldest cutlery).
Blade: 5-inch, high-carbon steel forged for edge retention. Handle: Typically beechwood with 4 pins for full tang.
Era: Popularized by mountain men in the fur trade from the 1830s onward, with "Green River" becoming a standard for quality goods.