A correction: When I first picked up this bar, I had it filed as Sumitomo — the SMM-style monogram in a circle pointed straight at Sumitomo Metal Mining, and that’s how several auction listings had it tagged too. That was the best read based on the information available at the time. It was wrong. Here’s the full story.
The mark
The hallmark is an S over a stylized M inside a circle, usually with .999 stamped alongside it. For years, collectors and sellers read those intertwined initials as “SMM” and landed on Sumitomo Metal Mining, the Japanese mining giant. It’s an easy mistake — the letters fit, and Sumitomo is a real LBMA-listed silver producer. But the mark belongs to a small Arizona outfit: State of Maine Mining, pouring silver at Tombstone in the 1970s and early ’80s.
How the record got corrected
The reattribution comes from Holabird Western Americana, the Reno auction house that handles a lot of Western mining material. They’ve sold this exact ingot twice — November 2024 and February 2025 — and their catalogs state it plainly: the ingot is “hallmarked on the side with ‘SMM’ within a circle, which is the trademark for the State of Maine Mine in Tombstone, Arizona,” produced in the 1970s by Tombstone local and mine owner Charlie Escapule.
The broader market is still catching up. One prominent dealer lists these bars under a hedged dual name — “State Of Maine Mining Co / Sumitomo” — and as recently as 2022, an iCollector auction sold a 29.9-gram example outright as an “SMM Sumitomo Poured Silver Bar” for $160 plus premium. You’ll still see both names floating around eBay. If you’re hunting one, search both.
The mine
The State of Maine Mine sits in the Tombstone Mining District of Cochise County, Arizona — named for the state of Maine, pouring in the Arizona desert. It was a silver-gold producer going back to the late 1800s, described as “flourishing” in 1880, then quiet for decades.
The modern chapter starts in the early 1970s. According to local history from the ranch that now occupies the ground, a rich silver deposit was discovered, and State of Maine Mining bought the property from the Escapule family — longtime Tombstone locals. The company went big: a milling, distilling, and foundry operation, including a huge timber mill relocated from their operation in Montana and reassembled by the Maine Mine headframe. It never paid. Within about a year, the company shifted its processes to a property in Mexico and walked away from Tombstone.
The Escapules
Here’s the part that dates the bars. When the company left, the Escapule family got their property back — buildings and all — and went back to working the mine themselves, successfully, on a small scale “for quite some years.” The ingots, including the one in this post, were poured by Charlie Escapule: born and raised in Tombstone, a miner and rancher in his youth, a Korean War veteran who came home to work for the school district and the USDA before returning to mining in his forties. USGS records also tie the mine to the Escapule name and to Sierra Minerals Management from 1974 onward.
Dating
The company window is early 1970s, but the family’s small-scale production ran longer, which is why these ingots most likely date to the late ’70s into the early 1980s. The pour style supports that read.
Specs (typical)
.999 fine silver. The documented examples run from 1 oz pieces up through ~10 oz loaves (10.04 oz is the figure on the Holabird ingots; a 10.09 oz loaf has surfaced on eBay). Hallmark on the side of the bar rather than the face.
