Ktemaque 15 and Nacha Nimat 86 merged to form Mahicantuck Lodge #15:
"On Sun., Nov. 14th, over 65 members of Ktemaque and Nacha Nimat Lodges gathered at Camp Bullowa for the first official meeting of our new lodge. The new name for the Greater Hudson Valley Council Order of the Arrow lodge will be 'Mahicantuck Lodge #15, W.W.W.' and it's totem will be that of the historic 'Mastadon', where remains have been found in the Hudson Valley area.
Effective: Nov 14, 2021
The new officers were elected at this meeting."
Reference: New York OA Trader
Even though they were both chartered to Greater Hudson Valley Council, according to Project Magellan, Ktemaque 15, as part of the old NE-2B, was assigned to Section E-18, and Nacha Nimat 86, as part of the old NE-2A, was assigned to Section E-20. Now they've merged, I had to consult both the Project Magellan map and Section E-20 website's list of lodges, to decide that Mahicantuck 15 must be part of Section E-18.