A glacial lake at an elevation of , Budd Lake has a surface area of . It is 7–12 feet deep, and can have large algal blooms. The bog, created by thousands of years of decaying plant material, supports wetland plants such as black spruce and tamarack, which grow on the floating mass. The lake is recharged through groundwater seepage through a series of wetlands, and serves as the headwaters of the Raritan River's South Branch. It is closely bordered by U.S. Route 46 to the south, and Sand Shore Road to the east.