Derwood is an unincorporated area and census-designated place in east-central Montgomery County, Maryland. It lies just north of Rockville, southeast of Gaithersburg, southwest of Olney, and northwest of the greater Silver Spring, Maryland area. Derwood, originally "Deer Park" then "Deer Wood," is home to approximately 15,600 people.Derwood includes the neighborhoods of Derwood Station, Mill Creek Towne, Needwood Estates, Muncaster Manor, Muncaster View, Hollybrooke, Granby Woods, Park Overlook, Redland Crossing, Candlewood Park, Cashell Estates, Avery Forest, Avery Lodge, Avery Village, Bowie Mill Estates, Bowie Mill Park, Winters Run, Redland Station, Rolling Knolls, Emory Grove, and Shady Grove Crossing.Between 2009 and 2011, Maryland Route 200 was constructed directly through central Derwood affecting Cashell Estates and areas near Shady Grove Road.