The Three-Legged Buffalo is one of the most sought-after error coins in all of American numismatics. It was created when a Denver Mint pressman over-polished a damaged reverse die to remove clash marks, inadvertently grinding away most of the buffalo's right front foreleg in the process. Thousands of these coins were released before the error was caught, making them rare but not impossibly scarce.
To identify a genuine specimen, examine the reverse with a 5× to 10× loupe. The right front leg should be almost completely absent from the knee down, with only the faintest trace of the hoof possibly remaining. The key diagnostic is not just the missing leg — it is the accompanying die markers: a rough, pitted, moth-eaten texture on the Indian's neck and cheek area on the obverse, and small raised die lumps (die polishing artifacts) visible beneath the buffalo's belly on the reverse.
Perhaps the most telling diagnostic is the position of the motto E Pluribus Unum. On genuine Three-Legged coins, this motto is visibly separated from the buffalo's back, whereas on normal 1937-D nickels it touches the animal. Collectors pay extraordinary premiums for this variety because of its dramatic visual impact and storied history. Certified examples in any grade command serious money, but roughly 80% of raw Three-Legged coins offered for sale are altered fakes — authentication by PCGS or NGC is absolutely mandatory before any transaction.
The 1937 proof Buffalo nickel holds an unparalleled place in American numismatic history: it is the very last proof Buffalo nickel ever struck by the United States Mint. The proof series was discontinued after 1937, making this the final chapter of a proof program that began in 1913. Philadelphia struck just 5,769 of these special collector coins, giving them a mintage far below all circulating issues.
Proof Buffalo nickels of this era were struck on specially prepared planchets using highly polished dies, giving them deeply mirrored fields and frosted design devices — a contrast that creates the "cameo" effect so prized by collectors. A standard proof shows brilliant, mirror-like fields, while designated Cameo (CAM) proofs show a stronger frost-on-mirror contrast and command significant additional premiums above standard proof prices.
In PR-63 condition, expect values around $950–$1,100. A PR-65 example is worth approximately $1,250–$1,500. The finest known examples in PR-68 have sold for over $40,000 at Heritage Auctions — specifically, a PR-68 realized $40,250 in January 2012. Cameo-designated proofs at equivalent grades add a substantial premium. Survivorship rates are extremely high for this issue, with PCGS estimating around 5,000 specimens still extant.
Repunched mint marks (RPMs) occur when the letter punch used to sink the mint mark into the working die strikes more than once at slightly different positions, leaving ghost impressions or offset secondary marks alongside the primary. The San Francisco Mint produced at least six catalogued RPM varieties on 1937 nickels, with the most dramatic being the S/S/S configuration where three distinct S impressions are visible.
To find the repunching, use a 10× loupe and examine the S mint mark closely on the reverse below FIVE CENTS. Look for shadow shapes, partial letter outlines, or bumpy texture at the top, bottom, or sides of the primary S. The S/S/S RPM variant shows what appears to be a cascading, stacked effect — almost like three S letters slightly offset from each other. This is the most visually dramatic and most valuable of the six catalogued varieties.
Premium value depends heavily on the strength of the secondary impression and the coin's overall grade. Circulated examples with a clear RPM visible to the naked eye sell for $15–$30 above standard pricing. In MS-63 to MS-64 uncirculated grades, well-defined RPM coins bring $50–$100. The S/S/S variety in gem MS-65 condition with a bold, strong secondary impression has reached $150–$185 at auction, particularly when paired with excellent strike quality that shows the buffalo's full horn detail.
The Denver Mint produced an even larger catalog of repunched mint mark varieties than San Francisco in 1937 — at least nine distinct D/D RPM varieties have been catalogued by CONECA (RPM-001 through RPM-009). Each represents a working die where the D punch was applied more than once at a slightly different angle or position before striking began, leaving a secondary D impression that can be identified with magnification. Most collectors overlook this variety entirely, making it one of the most undervalued RPM series in the entire Buffalo nickel run.
Identifying a 1937-D RPM requires a 10× loupe and careful examination of the mint mark on the reverse, just below FIVE CENTS. The secondary D impression typically appears as a ghost outline, a slight bump on one side of the primary D, or a partial loop above or below the main letter. The strongest examples — particularly RPM-001, the most dramatic in the series — can show the secondary D nearly completely offset, making identification obvious even at lower magnification.
Because nine varieties exist, there is a wide range of premiums. Weak or faint D/D impressions add only modest value over a standard 1937-D. However, strong RPMs in gem MS-65 condition — especially the most dramatic early varieties in the series — have sold for over $185. These coins are also frequently overlooked by generalist coin dealers, meaning patient searchers who examine raw 1937-D coins at shows or estate sales occasionally find RPM specimens priced as ordinary dates. Strike quality on Denver coins also varies considerably; strong-strike examples already command premiums, and a strong-strike RPM is doubly desirable.
A doubled die occurs when the hub strikes the working die at a slightly different rotational angle during the hubbing process, creating a doubled image of all or some obverse design elements baked directly into the die. The 1937-P DDO-001 — catalogued by CONECA as Class VI (rotated hub doubling) — shows doubling primarily on the date digits and the letters of LIBERTY, and to a lesser degree on elements of the Indian's portrait. Because all coins struck from that die carry the same doubling, this is a true die variety, not a one-off mint error.
Identifying the DDO-001 requires a 10× loupe and good lighting. The doubling manifests as a distinct shelf or shadow on the south or southeast side of the date numerals — particularly noticeable on the 9 and 7 — and on one or more letters of LIBERTY above the Indian's portrait. The doubling in this variety is classified as Class VI (rotated), meaning the secondary image is rotated slightly rather than simply spread outward, giving it a distinctive angled-shadow appearance rather than the bold "notch" look of Class I doubling.
Values for DDO-001 exceed standard pricing for the date and grade, but the premiums are modest compared to the Three-Legged variety. Circulated examples where the doubling is still visible despite wear command $35–$75. In uncirculated grades of MS-63 to MS-64, these coins bring $100–$175. Gem MS-65 examples with sharp, well-defined doubling can exceed $250. The variety is underappreciated relative to its collectibility, and many examples pass undetected in raw coin lots — making it a rewarding find for collectors willing to spend time with a loupe at coin shows.
