Chicago Portage National Historic Site

Chicago Portage National Historic Site
IUCN category V (protected landscape/seascape)
Show map of Illinois Show map of the US Map of the U.S. state of Illinois showing the location of Chicago Portage National Historic Site
Location	4800 S. Harlem Ave., Lyons, Cook County, Illinois, USA
Coordinates	41°48′20″N 87°48′25″W / 41.80556°N 87.80694°W / 41.80556; -87.80694Coordinates: 41°48′20″N 87°48′25″W / 41.80556°N 87.80694°W / 41.80556; -87.80694
Established	1952
Governing body	Forest Preserve District of Cook County

The Chicago Portage National Historic Site is a National Historic Site in Lyons, Cook County, Illinois, United States. It is located in Chicago Portage Forest Preserve, at the junction of Portage Creek with the Des Plaines River, on the west side of Harlem Avenue on the line of 48th Street. Preserved within the park is the western end of the historic portage linking the Chicago River to the Des Plaines River, thereby linking the Great Lakes to the Mississippi River. A memorial depicting the portage of the French explorers is located at the parking area. A trail leads from the memorial down into the portage wilderness area.

The site commemorates the Chicago Portage first written about and used by French explorers Father Marquette and Louis Joliet during their exploration of the area between Lake Michigan and the Mississippi River. The portage crossed what was known as Mud Lake, which could be wet, swampy, frozen, or dry, depending on the season, and which has since been completely obliterated. Mud Lake extended roughly from the historic western end of the South Branch of the Chicago River (near today's Damen Avenue) to the Des Plaines River at this National Historic Site. These explorers understood the importance of the easiest crossing of the continental divide between the Gulf of Mexico and Atlantic Ocean watersheds.