From Harriman Trails – A Guide and History by William Myles (1991):
Lake Nawahunta was created in 1915 by the construction of a dam across Lewis Brook, a tributary of Queensboro Brook. The land did not belong to the Park then and it was built to be a trout hatchery. It is a small lake, 7-10 feet deep, visible from Seven Lakes Drive just south of the Silvermine Ski area.
… the name Nawahunta is Mohegan for “place of trout”.
A NY – NJ Singles Hiking Club