To find the nearest fire hydrant to a home or business, a request may be made in writing to local Emergency Service representatives; this letter is called a "Request for Letter of Protection." As of 2014, there is no definitive way to find a fire hydrant.
In Florida and across the United States, the Bureau of Safety Services is mapping out the locations of fire hydrants through GPS tracking. This is done by manually locating each and every fire hydrant and using GPS to mark its coordinates.
There is also the adopt-a-hydrant program that is being developed in certain states, such as North Carolina. This program has volunteers track down fire hydrants and help with maintenance.