According to the United States Census Bureau, the township had a total area of 80.316 square miles (208.018 km2), including 75.090 square miles (194.483 km2) of land and 5.226 square miles (13.534 km2) of water (6.51%).
Unincorporated communities, localities and place names located partially or completely within the township include Apshawa, Awosting, Bearfort Waters, Beaver Pond, Boy Scout Lake, Browns, Buckabear Pond, Camp Hope, Cedar Pond, Charlotteburg, Clinton, Clinton Reservoir, Cooper, Dunker Pond, Echo Lake, Forest Hill Lake, Fox Island, Gordon Lakes, Green Valley Park, Greenwood Lake, Greenwood Lake Glens, Hacks Pond, Henion Pond, Hewitt, Himes Pond, Lake Lockover, Lakeside, Lindy Lake, Littletown, Lower Mt. Glen Lake, Macopin, Matthews Lake, Moe, Mount Laurel Lake, Newfoundland, Oak Ridge, Pettets Pond. Pine Crest Lake, Pinecliff Lake, Postville, Shady Lake, Smiths Mills, Surprise Lake, Terrace Pond, Upper Greenwood Lake, Upper Macopin, Upper Mt. Glen Lake, Uttertown, Vreeland Pond, West Milford Lakes, West Pond, Wonder Lake and Zeliff Pond.
The township borders the municipalities of Bloomingdale and Ringwood in Passaic County; Butler and Kinnelon in Morris County; Vernon and Hardyston in Sussex County and Warwick in Orange County, New York.
Highlands Preserve is a 224-acre (91 ha) county park that is located off Union Valley Road and adjacent to Abram S. Hewitt State Forest.