According to Rowan Jacobsen, the writer who celebrates great American Foods in American Terroir, Savoring the Flavors of Our Wood, Water, and Fields, the only suitable terroir in the world for maple syrup is the Greater Northeast, described as a triangle running from Michigan to New Brunswick (Canada) to West Virginia.
The University of Maine Cooperative Extension provides resources and expertise on maple syrup production on its website, as does the University of Vermont Extension Maple Program.
Directories of Maple Syrup & Sugar Makers in U.S. & Canada:
Maple Syrup Producers Association of Connecticut offers a map and brochure of sugar houses open to the public
Maine Maple Producers Association maintains a directory of members
Massachusetts Maple Producers Association, a non-profit organization dedicated to the preservation and promotion of maple sugaring in Massachusetts (a state where there are more than 250 sugaring operations), maintains a directory of Massachusetts sugar makers, who sell maple products to the public.
Michigan Maple Syrup Association offers a map of producers in the state
Minnesota Maple Syrup Producers Association maintains a directory of members
New Brunswick Maple Syrup Association during its Maplelicious Fest offers a “maple trail” map noting producers that in March & April invite the public into their “sugar camps”
New Hampshire Maple Producers Association maintains a directory to find a Sugar House in New Hampshire
New York Maple Pure maintains a directory of certified maple syrup producers in New York State that follow safe food handling and environmentally responsible practices.
Ohio Maple Producers Association maintains a directory of producers of maple syrup and products
Ontario Maple Syrup Producers Association maintains a directory and map of producers of maple syrup and products in the province
Pennsylvania Maple Syrup Producers Council has links to associations of maple producers in Five distinct areas of the state, which maintain directories of local producers
The Rhode Island Department of Environmental Management’s Division of Agriculture maintains a list of maple syrup producers in Rhode Island
Vermont Maple Sugar Makers’ Association maintains a directory of maple syrup producers in Vermont, and notes that “maple” is Vermont’s Official Flavor.
West Virginia Maple Syrup Producers Association maintains a map and info on over 50 producers in the state
Wisconsin Maple Syrup Producers Association provides a Buy Local map where Pure Maple Syrup is for sale