Rock Piles About a Mile From Father Ralse/Abenaki site

Reader Josh W. writes:

Recently, I identified two mounds on my families property (mounds are approximately at  44°48'43.99"N,  69°53'16.48"W) in Madison, Maine. They are just above the Kennebec river's flood plain except for the worst floods. I don't think the flood of 1987 reached that high.

Anyways, these two mounds are well overgrown with trees and bush, but the mounds appear to be made up of slate-like pieces of rock stacked up, with a very large, and unique, pile of quartz between the two mounds. The quartz is unusual, as, while it is present here or there on the property, this one spot has loads of it. The mounds are clearly man-made and are near some bedrock outcroppings, which are also uncommon on the property. Some of the slate appears to be stacked atop bedrock (or large traveling boulders, deposited during the last ice age and only appearing to be bedrock).

My home is about a mile from well documented native populations, including the massacre of 1724 (and the events surrounding http://en.wikipedia.org/wiki/S%C3%A9bastien_Rale). I was wondering if my description of these mounds is similar to anything else found in this area, or anywhere the Abenaki tribes were located. Should I investigate further, or is it better just to leave them to be slowly absorbed by the wilderness?

UPDATE: There is no powerline expansion happening here, the land is currently Weston property and has been since homesteading days about 200 years ago (our house is 5 years from our bicentennial). Its kind of a strange subject talking about the land which the was given away to our family by the State of Massachusetts, in connection with the previous inhabitants which hadn't really been gone from the area when the land was deeded. The earliest of our ancestors settled in 1771, less than 50 years after the Rale incident and in living memory for people at the time. Strange indeed. 

The area is not far north of the falls in Madison and the well known Norridgewock village, and just south of where the Carrabassett River empties into the Kennebec. The mounds are only a couple feet away from the old Caribou Trail, a trail which, according to our ancestors and other oldtimers in the area, was the caribou migration trail where they would walk pretty much single file through the area, year after year, the ground so well-trod that parts of it are still thought to exist today. At least that is the local mythology, but certainly it is true to some extent.

In addition to the mounds, there are a number of other possible features in the area, along a run of exposed bedrock, the only such exposed places in the nearby area (on our property, anyways). We never had a brickworks on the property, that I know of, but there are hematite-rich very red clay deposits only feet away from the mounds I described, and some evidence of a small dam, which may have been when the area was used as scrub pasture, too wet in patches to plow, which most of the rest of the property underwent over the years. Now it is timberstand.

There must have been an enormous presence of people here over the millenia, with the falls and the caribou trail which you can still find loads of arrowheads and what not around. I can't believe it never occured to us to check for ancient structures, but the area has been so overgrown in the past 100 years since large-scale agriculture died down, that things have been hidden from view.