Grand Detour, Illinois
（重定向自Grand Detour）
![](/Images/godic/202501/16/Grand_Detour,_IL_St._Peter's_Church_010909.JPG")
![](/Images/godic/202501/16/Location_map_of_Ogle_County,_Illinois.svg0909.png")
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![The Rock River in Grand DetourThe Sheffield Hotel in Grand Detour, purchased by Orson Welles's father](/Images/godic/202501/16/Rock_River_Grand_Detour10910.jpg")
Grand Detour is an unincorporated census-designated place in Ogle County, Illinois, United States. As of the 2010 census, its population was 429. The village is named after an odd turn in the Rock River, which flows north past the village, rather than its normal southwestern course. John Deere invented the steel plow in Grand Detour, and the John Deere House and Shop is a U.S. National Historic Landmark.