Question: What city in Putnam County holds the start of The Mug Race?

Context paragraphs:
Palatka, Florida: Palatka (pronounced puh-lat-kuh) is a city in Putnam County, Florida, United States.  The population was 10,558 at the 2010 census.  It is the county seat of Putnam County.  Palatka is the principal city of the Palatka Micropolitan Statistical Area, which is home to 72,893 residents.  The city is also home to St. Johns River State College, St. Johns River Water Management District Headquarters, and Ravine Gardens State Park.  The area is well known for its local festivals, most notably the Florida Azalea Festival and the Blue Crab Festival.

Donald B. Smith: Donald Blaine Smith (born September 1947) is the 53rd Sheriff of Putnam County, New York and a retired United States Army General.  He is a lifelong registered member of the Republican Party, and was first elected Sheriff on November 6, 2001.  He assumed the duties of Putnam County Sheriff on January 1, 2002.  Immediately prior to becoming the Sheriff of Putnam County, he had served as the Deputy County Executive of Putnam County.

Putnam County Port Authority: Putnam County Port Authority is a public corporation established to develop and manage port facilities in Putnam County, Florida.  Created in 1967 by Florida Law 67-1967, the port district is one of 16 in the Sunshine State.  The Port Authority also owns and maintains industrial and commercial development areas.  The Putnam County Board of County Commissioners serves as the governing body of the entity.  Considered a component unit, elected county officials set policies and oversee major expenditures.  The board does not hold regular meetings of the Port Authority; rather, meetings are held on a situational basis.  Putnam County Public Works and the Port Authority are understood as blended units; as such, day-to-day operations are carried out by the office of Public Works.

Unionville Square Historic District: Unionville Square Historic District is a national historic district located at Unionville, Putnam County, Missouri.  The district encompasses 61 contributing buildings and 1 contributing structure in the central business district of Unionville.  It developed between about 1872 and 1951, and includes representative examples of Italianate and Colonial Revival style architecture.  Notable buildings include the Putnam County Courthouse (1923-1924), O. J. Townsend Block (1889-1890), United States Farm Service Agency (1951), United States Soil Conservation Service (1951), Putnam County Library (1951), Putnam County Historical Museum (1912-13, 1928), United States Post Office (1930-1931), Unionville City Hall (1894-1897), and the Putnam County Senior Center (1892).

Greencastle, Indiana: Greencastle is a city in Greencastle Township, Putnam County, Indiana, United States, and the county seat of Putnam County.  It was founded in 1821 by Ephraim Dukes on a land grant.  He named the settlement for his hometown of Greencastle, Pennsylvania.  Greencastle was a village or town operating under authority of the Putnam County commissioners until March 9, 1849, when it became a town by special act of the local legislature.  Greencastle, Indiana, officially became a city after an election held on July 8, 1861.  The first mayor of Greencastle was E. R. Kercheval, a member (during his lifetime) of the Freemason Temple Lodge #47.  The city became the county seat of Putnam County.  The population was 10,326 at the 2010 census.  It is located near Interstate 70 approximately halfway between Terre Haute and Indianapolis in the west-central portion of the state.  Greencastle is well known as being the location of DePauw University.

Mug Race: The Mug Race is an annual sailboat race held on St. Johns River in the US state of Florida.  Billed as the "World's Longest River Race", the course starts in Palatka and ends in Jacksonville.  To compete, masts must be under 44 feet in order to clear all bridges along the course.  The Mug Cup is awarded to the first boat to complete the 38.5 mile course from the starting line at Memorial Bridge to the finish line at Buckman Bridge.  Additionally, there are over 100 class specific trophies

The Ride Solution: The Ride Solution is a non-profit agency that provides public transportation in the city of Palatka, as well as other communities in Putnam County, Florida.  The Palatka Union Depot serves as the systems hub, offering access to Greyhound and Amtrak routes.  Inter-county routes connect Putnam County to Jacksonville's JTA transit system, and the Gainesville Regional Transit System.  Due to the diffused population and rural nature of Putnam County, adequate public transportation is difficult to accomplish.  As such, a secondary goal of Ride Solution is to address rural transportation issues.

Putnam Transit: Putnam Transit or Putnam Area Rapid Transit (PART) is the provider of bus transit in Putnam County, New York.  An agency of the Putnam County government, Putnam Transit came into service in the mid-1970s as a startup system in the wake of growing suburbanization of Putnam County and rising gas prices.

Putnam County Business Park: Putnam County Business Park is a commercial development area located in Palatka, Florida.  The 257 acre site borders Palatka Municipal Airport and is in close proximity to Putnam Community Medical Center and St. Johns River State College.  The business center is owned by Putnam County and Putnam County Port Authority.  Alorica was the only tenant occupying the park until it closed in 2015.  The telecommunications and business solutions company operated a call center on the property.  The former Alorica call center building is for lease.  Other sites are shovel ready.

Putnam County Trailway: The Putnam County Trailway is a paved 12 mi bicycle and pedestrian trail in Putnam County, New York.  With few exceptions, it follows the former right-of-way of the New York and Putnam Railroad from the northern end of the North County Trailway at the Putnam County line in Baldwin Place north, then east, to Carmel.  In 2011 the trail was extended east to Brewster.  As of summer 2017, a final section bypassing portions of Putnam Ave in Brewster is popularly ridden, but remains formally closed with construction barriers and signs.  The Brewster station of the Metro-North Railroad is a short distance away.

Supporting paragraphs: Mug Race Palatka, Florida
Answer: Palatka