The Town[3] of Rietbrock is located in Marathon County, Wisconsin, United States.

The town contains one of the four 45×90 points of the world, where the 45th parallel north and 90th meridian west intersect.

According to the United States Census Bureau, the town has a total area of 33.8 square miles (87.5 km2), all of it land.

The Marathon County Park Commission has posted a geographical marker[5] that identifies the spot (45°N, 90°W) of the exact center of the northern half of the Western Hemisphere, meaning that it is a quarter of the way around the world from the Prime Meridian and halfway from the equator to the North Pole.

The racial makeup of the town was 99.24% White, 0.11% African American, 0.32% Asian, and 0.32% from two or more races.