https://www.dekut.com/Education/montana-state-quarter-dollar-without-copper-layer-%7C-mintage-world/ Montana quarter dollar error coin in circulation is worth more than face value because of its composition. After analysing the George Washington obverse of the coin it was found that the coin was in circulation as it had a San Francisco Mint mark. Sat, 15 Oct 2016 06:54:28 UTC en