Collecting state quarter errors can lead to finding high-value coins prized by collectors due to their rare mistakes. Here are 11 valuable state quarter errors to look for:

Types of Coin Errors
Planchet Errors: Incorrect or blank coin planchets, misaligned or clipped designs.
Die Errors: Mistakes with the dies such as typos or double-die errors.
Strike Errors: Improper strikes like off-center or misaligned strikes.

Notable State Quarter Errors
2005-P Minnesota Quarter with Extra Tree: Look for small lumps to the right of the smallest tree.
1965 SMS Washington Quarter Broadstruck: Look for extra space around the coin's back and a highly reflective surface.
2004-D Wisconsin Quarter with Extra High Leaf: An extra leaf points up beside the corncob.
2004-D Wisconsin Mint Mark Quarter with Extra Low Leaf: An extra leaf points down next to the corncob.
2009-D District of Columbia Double Die: Look for an extra "Ell" in "Ellington" and doubled details in the piano keys.
1999-P Connecticut Quarter Feeder Finger Error: Feeder finger jamming can create stuck quarters.
2002-P Indiana Quarter Struck on Dime Planchet: Misshapen coins due to smaller planchets.
1999-P Susan B. Anthony Dollar/Georgia Quarter Hybrid: Mixed designs from a dollar and a quarter.
2000-P Maryland Quarter/Dime Hybrid: Washington's profile reaches the coin's edges due to a smaller planchet.
2000-P South Carolina Quarter Reverse Die Break: Look for a die break on the reverse side.
2007-P Idaho Quarter with Cud Error: A raised area on the coin's edge due to a die break.

Finding these errors can significantly increase the value of your coin collection. Happy hunting!