Possible Clues:

• Sherwood Forest flora
• I guess they're like supermarkets for squirrels
• Wine barrel trees
• A race of trees
• It's flatly the classic hangouts for squirrels
• Thousand __, CA
• Many wine barrels come from them
• Horse race with odds OK, as evens?
• Some trees that squirrels like
• Dumbarton ___ (D.C. estate gifted to Harvard University)