I love how you have so much interest in this.
I don't believe in the Solutrean hypothesis, whereby Native Americans in the Northeast came from NW Europe in 20000 BC, because it would be so hard for a major expedition like that to go so far with such a big population. It's quite another thing to reject as impossible that a few explorers (like 5 to 30) crossed the North Atlantic in the c. 10,000 years between the Amerindians crossed the Bering Strait and before the Vikings.
I think it's unlikely that Irish or Vikings made a colony in New England before Columbus' time, because I think we would have found stronger evidence of it. But then, until they really started looking hard for it in Newfoundland, they didn't know where the Norse colony was there exactly either.
We know that Amerindians were at these sites for centuries before Columbus' time, probably going back thousands of years. They left interesting rock carvings called petroglyphs and were Algonquin people. They made cairns with stones and even made some interesting small forts or fort walls like the Narragansetts did with "Queen's Fort" in Rhode Island (National Register of Historic places.).
Queen's Fort, R.I.
They didn't do largescale irrigation and farming like in Mexico. I think that they probably didn't make the bigger stone chambers like at Upton either, because that relies on making arched ceilings, which is hard architecturally.
My best guess is that they didn't make the slab tunnels at Stonehenge USA or at Gungywamp either, but it's quite mysterious. The giant slab tunnels go beyond what I would expect from just a few colonial farming families in Salem, NH living and passing on the same property to eachother.