Compass sells homes in all 60 towns of Middlesex County, Massachusetts. Our coverage area includes the entire northeastern part of the state. Named after Middlesex county in southeast England, our Merrimack Valley community is the largest county in Massachusetts with over 1.6 million residents. Using our in-depth knowledge of local market statistics & seasonal data trends, we market your property correctly so it sells when it’s best for your timeline at the price that you want.