At some point they discovered that the old timers left enough gold in the tailings piles that it made sense to use modern techniques to reclaim that already out of the ground gold before selling the gravel. That triggered a multi-year legal fight to 'stop them from raping the land through gold mining'. Not only did they want the 'mining operation' stopped, now they also wanted the current owners to 'properly' remediate ancient mines scattered through the property. Some of these mine were legitimately historical places where South American's were coming north to mine Turquoise and Silver several hundred years ago.
We ended up not only losing access to the tailings piles for gravel use, but were then required to clean up the mess left by mining operations that had not existed for a hundred years or more. It shaped the way I view most people that claim to want to save the environment to this day. There is rarely any middle ground anymore and has become and all or nothing platform.
New England went glaciers -> tundra -> grasslands -> forests managed by native peoples -> un-managed forests.
The ecological state theses environmentalists are promoting is basically the status quo of the early 1700s and late 1800s through present day. It's hard to define what the "natural" state is since it went from periods of rapid change to various states shaped by human activity with little in between. Generally speaking most people consider the forests as they would have existed as managed by the natives prior to European settlement as the state that is most worthy of reconstruction.
This is magical thinking; the First Nations are, and were, human. The Huron, for instance, would move their settlements once they had "used up" all the readily available resources (mostly game animals) in the area. The First Nations were only better "custodians" of the land because they lacked the means to abuse the land as thoroughly as European "settlers".
Relocating (and they didn't relocate far, remember this is inhabited land after all, you can't just set up shop on the neighbor gang's turf) is the native equivalent of leaving a field fallow. But because the natives were working with animal and plant species the feedback loop is potentially decades long (depending on local resources) vs farmers who will leave a field fallow every few years.
I agree that they would have left the place barren had they had the means but you have to consider that what they were doing was stable on a 500+yr timeline which is a pretty good run.
My point here is that the impenetrable thicket a lot of environmentalists want to maintain is not particularly representative of "peak forest". I'm sure they all want to see blueberries and 200ft pines but just doing nothing won't achieve that because that's not a state that new england forests can (and certainly not today since we've got all sorts of invasive species and pests) get themselves into without human intervention either directly on a particular parcel of land or on enough near proximity land to influence the ecology of the parcel in question.
I agree that we should not indulge in "magical thinking", but non-American cultures display a wide variety of sensibilities with respect to defining "used up". There are traditions even within Europe that are relatively respectful of carrying capacity, but they have mostly been trampled on by industrialization and capitalism. It's entirely possible that native American resource management was closer to these older European traditions than those of the last 200 years.
I don't know how concerned those people were with sustainability or with being custodians of the land. But, even if they cared nought about such things, that need not mean that the state of the forest during their reign is not a worthy target for modern-day conservationists.
glaciers -> tundra -> grasslands -> forests managed by native peoples -> decimated forests due to settler activities -> depopulation and deindustrialization -> un-managed forests
glaciers -> tundra -> grasslands -> forests managed by native peoples -> unmanaged forests -> decimated forests due to settler activities -> depopulation and deindustrialization -> un-managed forests
Much of New England was clear-cut, either to harvest old-growth timber or for farmland. The forests we see today date to after the westward expansion, when farmers left the rocky New England soils for easier tilling in the Midwest and Great Plains states. So really, when people want to conserve the land in that state, they're saying "let's let the new-growth forests come back and maybe become old-growth forests again."