The Rocky River is a 28.3 miles (45.5 km) stream located in the southwest part of the U.S. state of Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

 that flows into the St. Joseph River

St. Joseph River (Lake Michigan)

The St. Joseph River is a river, approximately long, in southern Michigan and northern Indiana in the United States. It drains a primarily rural farming area in the watershed of Lake Michigan...

 at 41°56′33"N 85°37′59"W in the city of Three Rivers

Three Rivers, Michigan

Three Rivers is a city in St. Joseph County in the US state of Michigan. The population was 7,811 at the 2010 census.Three Rivers derives its name from the confluence of the St. Joseph River with its tributaries the Rocky and Portage Rivers. It is the home of St...

 in St. Joseph County

St. Joseph County, Michigan

-Demographics:As of the census of 2000, there were 62,422 people, 23,381 households, and 16,600 families residing in the county. The population density was 124 people per square mile . There were 26,503 housing units at an average density of 53 per square mile...

. The Rocky River, along with the St. Joseph River and the Portage River, are the three rivers from which the city of Three Rivers takes its name.

The Rocky River rises in southwest Marcellus Township

Marcellus Township, Michigan

Marcellus Township is a civil township of Cass County in the U.S. state of Michigan. The population was 2,712 at the 2000 census. The Village of Marcellus is within the township.The Township Hall is located at 13163 Marcellus Highway, Marcellus, MI, 49067....

 in Cass County

Cass County, Michigan

Cass County is a county in the U.S. state of Michigan. As of the 2000 census, the population was 51,104. It is part of the South Bend–Mishawaka, IN-MI, Metropolitan Statistical Area which has a total population of 316,663 and is sometimes considered part of Greater Michiana...

 at 41°59′43"N 85°51′04"W. It flows to the northeast, arcing gently to the southeast before turning sharply to the south in eastern Flowerfield Township

Flowerfield Township, Michigan

Flowerfield Township is a civil township of St. Joseph County in the U.S. state of Michigan. The population was 1,592 at the 2000 census.-Geography:...

, shortly after being joined by the Flowerfield Creek. It then flows mostly southward until joining the St. Joseph River in Three Rivers.

The Rocky River watershed encompasses over 112000 acres (45,324.8 ha) and drains all or portions of the following cities and townships:

• In Cass County
  Cass County, Michigan
  Cass County is a county in the U.S. state of Michigan. As of the 2000 census, the population was 51,104. It is part of the South Bend–Mishawaka, IN-MI, Metropolitan Statistical Area which has a total population of 316,663 and is sometimes considered part of Greater Michiana...
  
  
  • Marcellus Township
    Marcellus Township, Michigan
    Marcellus Township is a civil township of Cass County in the U.S. state of Michigan. The population was 2,712 at the 2000 census. The Village of Marcellus is within the township.The Township Hall is located at 13163 Marcellus Highway, Marcellus, MI, 49067....
    
    
  • Newberg Township
    Newberg Township, Michigan
    Newberg Township is a civil township of Cass County in the U.S. state of Michigan. The population was 1,703 at the 2000 census.- Communities :...
    
    
  • Penn Township
    Penn Township, Michigan
    Penn Township is a civil township of Cass County in the U.S. state of Michigan. The population was 1,902 at the 2000 census.Penn Township is the location of the Bonine House, a lookout post on the Underground Railroad, on the corner of M-60 and Penn Road...
    
    
  • Volinia Township
    Volinia Township, Michigan
    Volinia Township is a civil township of Cass County in the U.S. state of Michigan. The population was 1,174 at the 2000 census. When the township was organized in 1833, it was at first named Volhynia, after the province in Poland. It is believed to have been given to honor General Thaddeus...
    
    

• In Kalamazoo County
  Kalamazoo County, Michigan
  -Air Service:*The Kalamazoo & Battle Creek Metro Area is served by Kalamazoo/Battle Creek International Airport.-Interstates:* I-94* I-94 Business Loop-US highways:* US-131*  BUS US 131-Michigan State Trunklines:* M-43* M-89* M-96...
  
  
  • Prairie Ronde Township
    Prairie Ronde Township, Michigan
    Prairie Ronde Township is a civil township located in the extreme southwestern corner of Kalamazoo County in the U.S. state of Michigan. The population was 2,086 at the 2000 census.Prairie Ronde is the birthplace of the women's suffragist Olympia Brown....
    
     (via Flowerfield Creek)
  • Schoolcraft Township
    Schoolcraft Township, Kalamazoo County, Michigan
    Schoolcraft Township is a civil township of Kalamazoo County in the U.S. state of Michigan. The population was 7,260 at the 2000 census. The township is named for Henry Schoolcraft, noted for conducting many early land surveys throughout Michigan....
    
     (via Spring Creek)
  • Texas Charter Township
    Texas Charter Township, Michigan
    Texas Charter Township, officially named the Charter Township of Texas, is a charter township of Kalamazoo County, in the U.S. state of Michigan. As of the 2000 census, the township population was 10,919...
    
    

• In St. Joseph County
  St. Joseph County, Michigan
  -Demographics:As of the census of 2000, there were 62,422 people, 23,381 households, and 16,600 families residing in the county. The population density was 124 people per square mile . There were 26,503 housing units at an average density of 53 per square mile...
  
  
  • Fabius Township
    Fabius Township, Michigan
    Fabius Township is a civil township of St. Joseph County in the U.S. state of Michigan. The population was 3,285 at the 2000 census.-Geography:...
    
     (via Kerr Creek)
  • Flowerfield Township
    Flowerfield Township, Michigan
    Flowerfield Township is a civil township of St. Joseph County in the U.S. state of Michigan. The population was 1,592 at the 2000 census.-Geography:...
    
    
  • Lockport Township
    Lockport Township, Michigan
    Lockport Township is a civil township of St. Joseph County in the U.S. state of Michigan. The population was 3,814 at the 2000 census.-Geography:...
    
    
  • Park Township
    Park Township, St. Joseph County, Michigan
    Park Township is a civil township of St. Joseph County in the U.S. state of Michigan. The population was 2,699 at the 2000 census.The township was originally part of Flowerfield Township and was set off as a separate township in 1838.-Geography:...
    
    
  • Three Rivers
    Three Rivers, Michigan
    Three Rivers is a city in St. Joseph County in the US state of Michigan. The population was 7,811 at the 2010 census.Three Rivers derives its name from the confluence of the St. Joseph River with its tributaries the Rocky and Portage Rivers. It is the home of St...
    
    

• In Van Buren County
  Van Buren County, Michigan
  -Parks, preserves, natural areas:* Dunes Parkway, an 84 acre preserve of dunes in Covert Township* Jeptha Lake Fen Preserve, a 49 acre preserve in Columbia Township...
  
  
  • Porter Township
    Porter Township, Van Buren County, Michigan
    Porter Township is a civil township of Van Buren County in the U.S. state of Michigan. The population was 2,406 at the 2000 census.-Geography:...
    
    (via Sheldon Creek, Flowerfield Creek, and Four County Drain)

Tributaries

• (left) Kerr Creek
  • Little Pleasant Lake
    • Pleasant Lake
• (left) Armalege Drain
  • Goose Lake
• (right) Flowerfield Creek
  • (right) Spring Creek
• (right) Four County Drain
• (left) Ayers Lake
• (right) Sheldon Creek
  • (right) Lewis Lake
    • Mud Lake
• (left) Pickerel Lake
  • Skyhawk Lake
  • Streaters Mill Pond
  • Bogart Lake
• (right) Huyck Lake