Meteorites Found in Montana: 7 Documented
Montana has 7 officially recognized meteorites — 0 witnessed falls and 7 finds. The largest, Twodot (H6 — ordinary chondrite (high iron)), weighed 21.4 kg. The record here spans 112 years — from Illinois Gulch in 1899 to Choteau in 2011.
| Name | Classification | Mass | Fell / Found | Year | GPS |
|---|---|---|---|---|---|
| Twodot | H6 | 21.4 kg | Found | 1999 | 46.700, -110.133 |
| Roundup | Iron, IIIAB | 17.6 kg | Found | 1990 | 46.783, -108.567 |
| Choteau | Pallasite, ungrouped | 8.5 kg | Found | 2011 | withheld |
| Lombard | Iron, IIAB | 7 kg | Found | 1953 | 46.100, -111.400 |
| Harlowton | Iron, IAB-ung | 4 kg | Found | 1975 | 46.433, -109.833 |
| Illinois Gulch | Iron, ungrouped | 2.5 kg | Found | 1899 | 46.683, -112.550 |
| Livingston (Montana) | Iron, IIIAB | 1.6 kg | Found | 1936 | 45.600, -110.583 |
Reading the classifications
The most common meteorites — stony, with visible metal flecks. H = high iron content, L = low, LL = very low. The digit (3–6) says how much the parent asteroid heated it: 3 is the most pristine.
Primitive, carbon-bearing stones that predate the planets — some carry water-bearing minerals and amino acids. Fragile and rare on the ground.
Solid nickel-iron from the shattered cores of asteroids. Dense, magnetic, and the easiest meteorites to recognize — most of the biggest US finds are irons.
The showpieces: pallasites are gem-quality olivine suspended in polished metal, from the core-mantle boundary of destroyed asteroids.
Volcanic rocks from bodies large enough to melt — most trace to the asteroid Vesta; the rarest are from the Moon and Mars.
Frequently Asked Questions
How many meteorites have been found in Montana?
7 meteorites from Montana are officially recognized in the scientific record — 0 witnessed falls and 7 finds. The largest is Twodot at 21.4 kg.
Can I hunt for meteorites in Montana?
On BLM-managed public land, casual collecting is legal without a permit: surface finds, up to 10 lb per person per year, personal use only. National parks prohibit all collecting, and on private land the meteorite belongs to the landowner. Always verify land status before hunting.
How do I know if a rock is a meteorite?
Quick field checks: meteorites are unusually dense, most attract a magnet (iron-nickel content), fresh ones have a thin black fusion crust, and many show regmaglypts (thumbprint-like depressions). Slag and magnetite are the common false alarms.
⚠️ Always verify current regulations, weather conditions, and access requirements before visiting any location. Information provided is based on community submissions and may not be current or accurate.
Coordinates are historical find locations from the scientific record, often approximate — not guaranteed collecting spots; verify land status and permissions before hunting. Source of record: Meteoritical Bulletin Database (Meteoritical Society).