Some more exploration revealed the following:
At about 1300 feet on a 318 degree bearing, are first this massive boulder, then an outcrop with propped boulders. The outcrop has the bent tree with rocks still piled on the trunk, which was shown on 11/3/11. This site would correspond to summer solstice and Pleides set, according to the very useful "Stupid Sheet" from Rockpiles.blogspot.
Finally, across a lake and on a hill 3300 feet away from the boulder chamber stands this 7-foot tall propped boulder. It is the only large boulder on the hill, and has a somewhat pointed shape, like the one above.
Painting the view from the boulder chamber is impractical, since the markers would appear tiny, especially in artwork viewed on computer monitors and other digital devices.
One thing that has always impressed me is how many alignments appear in northern RI. Some are probably coincidence, but others look deliberate, especially when the markers are large propped boulders. This site is actually within reasonable hiking distance from some others I have shown, so the question is why so many, and to what purpose? One can see the difficulties involved in using these aligned boulders for accurate solstice readings: the observer would be looking at a distant marker against a blinding sun. Perhaps they were used for observations of the Pleiades and other constellations, and had some ceremonial use. They may have been a way to organize the landscape in respect to the seasons.