[3] In 1997, the family's Seven Islands Land Company is believed to be the fourth largest private landowner in the United States, according to an analysis by Worth magazine.
In that year, Pingree, correctly believing that his city would cease to be a major port, started purchasing vast tracts of softwoods and hardwoods as an investment hedge.
Development on the Pingree's Seven Islands Land Company property, much of which surrounds Baxter State Park and the Allagash River, is heavily restricted.
In 2001, Pingree Associates announced they had negotiated an arrangement with the New England Forestry Foundation to sell undevelopable easements on three-quarters of their nearly 1 million acres (4,000 km2).
The agreement created the largest conservation easement in American history, effectively putting an area larger than the state of Rhode Island off-limits to development.