The subject coin here is the 1900-O/CC Morgan Dollar, a fantastic over mint mark coin that clearly shows the “O” mint mark of the New Orleans Mint superimposed atop the “CC” mint mark.
The Last Carson City Morgan Dollar: How the CC Mintmark Returned - Rare Collectibles TV
1892-CC Morgans went to vaults upon issue - Numismatic News
1900-O/CC result of Carson City shutdown - Numismatic News
Seated Liberty dollar - Wikipedia
PCGS Coin News
Errors & Varieties
1900 O/CC TOP-100 $1 MS, Coin Explorer
McDonald's Fiesta Coins, a Forgotten Promotion
US 1878-1921 Silver Morgan Dollar History
Morgan dollar coin hi-res stock photography and images - Alamy