As the forks wind through the area that has become Louisville's East End, they have contributed to the geography that has shaped the area. The origin of the name "Beargrass" is not clear, though local stories abound and it was written as "Bear Grass Creek" in early maps.
Lyndon Lore states, "The name Beargrass was originally Bear Grasse, because the bears came to the creek for water and also for salt from the salt licks which were located near Salt River.
The earliest settlements by Europeans in the area were built in the form of stations, or forts, along the banks of the creek. The three forks drain about 70 square miles (181 km²) of land, and occasionally flood.
The three main branches are the South, Middle and Muddy Forks. They separate in the headwaters just east of Downtown Louisville. The South Fork runs through Butchertown to west of Tyler Park, through the Poplar Level area (where the Beargrass Creek State Nature Preserve is located) and eventually runs into Fern Creek. Eleven Jones Cave is located along this fork. It originally ran through downtown, but was rerouted in the 1850s.
The middle fork has two branches, called Weicher Creek and the Sinking Fork. Weicher Creek flows from the Hurstborne Area, and the Sinking Fork has its headweaters near Anchorage, Kentucky. They join in St. Matthews and flow through Cherokee Park until it meets the South Fork near the Bourbon Stockyards. The Muddy Fork rises at a stone springhouse in Windy Hills and runs parallel to the Ohio River and was rerouted during the construction of Interstate 71.
Although used just for drainage and as a scenic feature by the 20th century, in pioneer days it was navigable and used for that purpose.