Mountain Park is a city primarily in the western part of northern Fulton County in the U.S. state of Georgia, with a small portion extending less than into southeastern Cherokee County. As of the 2010 census, the city had a total population of 547.
It is bordered on three sides by Roswell, and on the west by an unincorporated area of Cherokee County; although the city extends into Cherokee County, the large majority of the city is located in Fulton County.
Lake Garrett is within the city, and downstream to the northwest Lake Cherful straddles the county line. Both lakes are gradually being destroyed by siltation, caused by development upstream in Roswell. The city sued in 2005. The developers contested their liability and claim the lakes have likely out-lived their "life expectancy", and the situation is likely caused by the natural flow of silt and sediment in the basin. Due to numerous pre-trial motions, the case did not go to court until October 2010, when the jury ruled in favor of Mountain Park but only awarded $45,000 in damages.
Mountain Park Volunteer Fire and Rescue was formed in 1977 and is an all-volunteer fire and EMS department providing emergency management services to the city. It also provides Automatic Aid to Roswell and mutual aid to the Fulton/Cherokee/Cobb County fire departments. It is state-certified and has roughly 20 members who are state or nationally certified for emergency services. In mid-May 2008 a severe thunderstorm with high winds from a just-dissipated EF2 tornado blew through, damaging many homes, some structurally. Severe flooding occurred in September, 2009 after a 13 inch per hour rain event. Flash flooding caused significant damage to several dozen houses and municipal structures. The Fire Department and Civic Building were significantly damaged and were reconstructed.
Law enforcement is provided by the Roswell Police Department on a contract basis.