The US mint released the Minnesota Quarter April 4, 2005, the 32nd release of the 50 State Quarters program. The quarter portrays the Common loon (Minnesota’s state bird), fishing, and the state map with its slogan on the coin’s reverse.
The Minnesota State Quarter was plagued with several Double Die Errors during its production, most notably the “Extra Tree”. The errors are mostly in the Philadelphia mint however there are also some varieties from the Denver mint.
For more varieties of errors, check out Ken Potter’s page