The Foster–Armstrong House is a historic house museum located at 320 River Road (County Route 521) in Montague Township of Sussex County, New Jersey.

[3] The farmhouse was added to the National Register of Historic Places on July 23, 1979, for its significance in agriculture, architecture, commerce, and exploration/settlement.

[4] The house is now part of the Delaware Water Gap National Recreation Area.

[5] The museum is managed by the Montague Association for the Restoration of Community History.

Foster and Armstrong operated a ferry across the nearby Delaware River.