The 1966 Washington Quarter is very common, especially since over 800 million of them were struck. Examples in circulated grades can still be found in circulation. Even examples in about MS60-MS63 condition can also be found in circulation. In MS64-MS66 condition they are little tougher to find, yet, can be purchased inexpensively. In MS67 condition it is scarce with less than a hundred examples graded by PCGS. In MS67+ condition is extremely scarce with less than handful of examples known and none being finer.