The Trust for Public Land is $6 million short of the $17 million is needs to purchase the land from R.D. Merrill Co. The all-cash deal must be completed by Oct. 31. If the trust does not buy the property, Merrill says it will be sold in as many as 53 20-acre parcels, which would allow for a house to be built on the properties.

The trust group hopes to keep the land largely untouched by luring six wealthy buyers to pay $3 million each to buy a 170-acre chunk that has strict conservation easements. Under that plan, about 98 percent of the land would remain undeveloped. So far, however, only three of six buyers have been found, and the trust has raised only a couple of million more in grants and loans.