Ding ding! I'd imagine it's quite an interesting place in the ASB, Iroquoia and its peoples on one side of the river, New Netherlands and its peoples on the other, and from the looks of the most recent English stocks map there appears to be a meaningful English Minority in the region.
That border is interesting too. It was defined vaguely at best for a really long time. The savvy viewer might notice that both of the traditional main Mohawk Iroquois towns are on the New Netherland side of it. By 1780 or so the valley was filling up with New Netherland citizens. The interactions of Mohawk people with German and Dutch settlers started to produce a hybrid culture with mixed children,
a mixed language, and mixed loyalties. Some of the western Iroquois nations started to worry that all this mixing was going to lead to the extinction of the Mohawk as a distinct people. Some officials downriver in New Amsterdam had similar worries. They all pushed for a defined border beyond which New Netherland would not assert jurisdiction over its citizens. They also shifted the center of Mohawk politics from the two eastern towns to a new town at Unundadages (Utica, NY) a bit more out of reach of pernicious Dutch and German influence.
Iroquois villages and members still on the New Netherland side remained Iroquois for a long while. The two Mohawk towns were enclaves where most people had dual citizenship. As Iroquoia evolved from a league of tribes into a territorial state, these wrinkles were ironed out, so that people east of the border might be Iroquois for cultural and ceremonial purposes, but legally they were equal to any other citizens of New Netherland.
The Adirondacks were still important as an Iroquois hunting ground. Iroquoia kept many land use rights there but ceded to New Netherland the responsibility for defense and control over boat and wagon trade. This shared use never completely ended. It survives today in the system of mutual provincial parks in the Adirondacks, nature preserves under the shared jurisdiction of both states.
The Oswego area is interesting too. Fort Oswego was a Dutch rather than an English foundation in ttl, but like in otl it altered the balance of power in the whole region. It made the Dutch a power in the Great Lakes for the first time. Its population was mostly Iroquois and Iroquois-Dutch creole until the 1820s or so, when lots of people began to move in from New England. Parts of northernmost New Netherland are actually majority Anglophone today, namely the area around Watertown, NY (which exists in ttl) and Lake Champlain. Oswego itself, as a relatively large town, probably mostly speaks the standard Dutch of the state, but in the rural areas around it there is lots of creole, with Anglophones concentrated in some neighborhoods and villages, especially in the Watertown area. The parts of Iroquoia immediately adjacent to the port are probably more Dutch and creole than Iroquois, but Iroquois culture is not far away, including the capital, Onondaga. And of course there is a French presence as well; the city of Frontenac (Kingston, ON) is not so far away, and even Canada possesses a bit of lakefront, including the Thousand Isles at Ontario's outlet.