Cascade is a city in Dubuque County and Jones County, Iowa, United States. The Dubuque County portion is part of Dubuque Metropolitan Statistical Area, while the Jones County portion is part of Cedar Rapids Metropolitan Statistical Area. The population was 2,159 at the 2010 census, up from 1,958 at the 2000 census. The city is located at the southwestern edge of Dubuque County, at the border of Dubuque and Jones Counties.Arguably the town's most notable historic event was the 1925 flood. Between 1880 and 1936 the town was connected to Bellevue via the Chicago, St. Paul & Milwaukee Railway Company.U.S. Route 151 runs through Cascade but in 2002 a four-lane bypass took traffic north around the city. Iowa Highway 136 runs from north to south through Cascade.