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 1,958 at the 2000 census, but is now estimated to be 2,122 (2006). The city is located at the southwestern edge of Dubuque County, at the border of Dubuque and Jones Counties. 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.