Long Valley is an unincorporated community and census-designated place (CDP)[8] in Washington Township, Morris County, New Jersey, in the United States.

[9][10][11][12] Once known as German Valley from its foundation during the colonial era, the community was renamed in response to anti-German sentiment during World War I.

[3] In 1705, a number of German Reformed, residing between Wolfenbüttel and Halberstadt, fled to Neuwied, a town of Rhenish Prussia, where they remained for two years before proceeding on to Holland.

Before arriving, their ship was blown off-course to the south, where they were carried into Delaware Bay and landed in Philadelphia.

From there, they embarked by land eastward to what became known as the "German Valley" in what was then called "Nova Caesaria" (New Jersey), located in today's Morris County.

The CDP extends northwest up onto Schooleys Mountain, rising 600 feet (180 m) above the valley, where it includes the community of Springtown.

To the southeast the CDP includes the lower Fox Hill Range, which rises 400 feet (120 m) above the valley.

The climate in this area is characterized by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold in the northern areas) winters.