High Quality Content by WIKIPEDIA articles! Spring Lake is a Borough in Monmouth County, New Jersey, United States. As of the United States 2000 Census, the borough population was 3,567. Spring Lake and its environs are known as the "Irish Riviera" because of the large Irish-American population in the area, with Spring Lake having the highest percentage of Irish Americans of any municipality in the United States. Spring Lake was formed as a borough by an Act of the New Jersey Legislature on March 14, 1892, from portions of Wall Township), based on the results of a referendum held on March 8, 1892. On February 24, 1903, the borough of North Spring Lake was annexed.