Green Tree at Mt. Vernon is located in Mr. Vernon which is the county seat of Jefferson County, Illinois. Located in the cross-roads of I-57 and I-64, Mt. Vernon is the perfect location to settle down. Home to many annual events and festivals, interactive historic landmarks, outdoor recreation adventures – there are things to do for everyone. With rich history, Mt. Vernon is now a thriving city with a growing arts culture. Stop by and see us anytime. We love to welcome visitors!