Native Americans

Several Native American tribes were the first humans to reach New New England, sometime before the 17th century. Though many got lost in the woods alone and subsequently had their souls and marrow consumed by wild thulhu (happens all the time), eventually a whole group of hunters came through together, and were able to survive and establish a settlement. What's more, they managed to find some lost squaws, too, and got a sustainable population! The first Indian village was Foggy Village.

History
The Indians spent most of their early time expanding Foggy Village. Though a lot of them were used to moving around, the thulhu around the village kept a lot of them from doing so, because they didn't want to get killed while carrying stuff from place to place.

When the first children were born to the refugees from Earth, they rejoiced, and quickly discovered that they have some control over thulhu. Many of these children became thulhu warriors, the precursors to Cultists, though the village elders feared they could grow dangerous.

Foggy Village eventually sent off other groups to found new villages, of which the only successes were Temple Rock, Equinox, and Sunnich. These successful villages made use of naturally (we think) appearing runes, which kept wild thulhu out. By following routes with runes along them, villagers from Equinox eventually met European settlers at Smithston.

Tribes
Native Americans of many different tribes have become lost and been accepted by New New England communities, but most are from the Massachussett region. The hunting group that founded Foggy Village was Wampanoag, so Wampanoag became the lingua franca for most immigrants, regardless of what tribes they were descended from and when they arrived.

Snipperwappers
The Snipperwapper tribe is descended from Young Snipperwapper, and elder of Foggy Village whose followers split from the village over disputes in thulhu training. The Snipperwappers argued that it was important to bring in dangerous thulhu to train better warriors, while the other elders, primarily Old Oxefeather didn't want dangerous thulhu anywhere near the village. The Snipperwappers later went to war with the people of Smithston, and have since retreated to Tharnath. They aren't all that violent anymore, but they are experts on training thulhu without the use of dodecahedra, which are a much more recent invention.

Where are they now?
After the witch hunts were over and peace came between the Indian and European groups, a lot of the Indians went to live in the European towns, which pretty nice technology, and the populations intermingled. Nowadays, most people have both Indian and European blood, and there are a few mostly-Indian villages still out there that practice the old ways. There are also a lot of full-Indian medicine men who have shops selling herbal remedies and telling fortunes.