Rock River ( Mississippi River ) - wikipedia Rock River ( Mississippi River ) Rock River Drainage basis of the Rock River Physical characteristics Main source Horicon Marsh north of Horicon, Wisconsin 43 ° 28 ′ 26 '' N 88 ° 38 ′ 41 '' W ﻿ / ﻿ 43.4738889 ° N 88.6447222 ° W ﻿ / 43.4738889 ; - 88.6447222 ﻿ ( Rock River origin ) River mouth Confluence with the Mississippi River at Rock Island, Illinois 551 ft ( 168 m ) 41 ° 28 ′ 57 '' N 90 ° 36 ′ 58 '' W ﻿ / ﻿ 41.4825326 ° N 90.6162489 ° W ﻿ / 41.4825326 ; - 90.6162489 ﻿ ( Rock River mouth ) Coordinates : 41 ° 28 ′ 57 '' N 90 ° 36 ′ 58 '' W ﻿ / ﻿ 41.4825326 ° N 90.6162489 ° W ﻿ / 41.4825326 ; - 90.6162489 ﻿ ( Rock River mouth ) Length 299 mi ( 481 km ) Basin features Progression Rock River → Mississippi → Gulf of Mexico GNIS ID 416824 Map all coordinates using OSM Map all coordinates using Google Export all coordinates as KML Export all coordinates as GPX Map all microformatted coordinates Place data as RDF The Rock River is a tributary of the Mississippi River, approximately 299 miles ( 481 km ) long, in the U.S. states of Wisconsin and Illinois. The river was known as the Sinnissippi to Sauk and Fox Indians ; the name means `` rocky waters ''. The river begins with three separate branches which flow into the Horicon Marsh. The northermost branch, the West Branch, begins just to the west of the village of Brandon in Fond du Lac County, Wisconsin and flows east and then south to Horicon Marsh. The South Branch rises north of Fox Lake in Dodge County and flows east through Waupun to the marsh. The East Branch rises southeast of Allenton in Washington County just west of the Niagara Escarpment, and flows north and west through Theresa to the marsh. Leaving the marsh, it meanders southward to the Illinois border ending about 300 miles later at the Mississippi River at the Quad Cities in Illinois and Iowa. During its course it passes through Watertown, collects the Crawfish River in Jefferson, and receives the Bark River at Fort Atkinson. In northern Rock County it receives the Yahara River, and flows southward through Janesville and Beloit into northern Illinois, where it receives the Pecatonica River 5 miles ( 8 km ) south of the state line. It flows south through Rockford, then southwest across northwestern Illinois, picking up the Kishwaukee River, passing Oregon, Dixon, Sterling and Rock Falls before joining the Mississippi at Rock Island. It was on the Rock River in Dixon where Ronald Reagan was a lifeguard. Reagan 's favorite fishing spot, now called `` Dutch Landing '' after Reagan 's nickname, was just southwest of Lowell Park on the Rock River. Shortly before merging, the Rock and Crawfish rivers cross Interstate 94. Both rivers flood the nearby land regularly, and lanes on I - 94 were temporarily closed in 2008 because of this flooding. There are 23 dams on the Rock River. These are in Theresa ( WI, 3 dams ), Waupun ( WI ), Horicon ( WI ), Hustisford ( WI ), Watertown ( WI, 2 dams ), Jefferson ( WI, 4 dams ), Indianford ( WI ), Janesville ( WI, 2 dams ), Beloit ( WI ), Rockton ( IL ), Rockford Fordham ( IL ), Oregon ( IL ), Dixon ( IL ), Sterling / Rock Falls ( IL, 2 dams ), Milan ( IL ) and Rock Island ( IL ). The Rock River Trail in Dodge County, Wisconsin The river is used for various water and paddling sports. The Rock River Water Trail is on the river from its headwaters above the Horicon National Wildlife Refuge in south central Wisconsin to the confluence with the Mississippi River at the Quad Cities of Illinois and Iowa 330 miles downriver. It crosses five counties in Wisconsin, six counties in Illinois and runs through 37 municipalities. The slow moving river passes scenic rural landscapes, wilderness areas and urban areas. The first two trailheads are at Waupun County Park in Waupun, Wisconsin and Rivers Edge Park in Theresa, Wisconsin and there are 32 additional access points in Dodge County, Wisconsin. The trail is part of the National Water Trails System and the first National Water Trail in Wisconsin and Illinois. Rock River Park is on County Road B about a half mile west of Johnson Creek, Wisconsin in Jefferson County, Wisconsin and offers river access and an artesian spring. Contents 1 Cities and villages along the river 2 See also 3 References 4 External links Cities and villages along the river Rock River flooding downtown Fort Atkinson, June 2004 The frozen Rock River near Oregon, Illinois Communities listed from north to south. Brandon, Wisconsin ( West Branch ) Waupun, Wisconsin ( South Branch ) Theresa, Wisconsin ( East Branch ) Mayville, Wisconsin ( East Branch ) Horicon, Wisconsin Hustisford, Wisconsin Watertown, Wisconsin Johnson Creek, Wisconsin Jefferson, Wisconsin Fort Atkinson, Wisconsin Indianford, Wisconsin Fulton, Wisconsin Janesville, Wisconsin Afton, Wisconsin Beloit, Wisconsin South Beloit, Illinois Rockton, Illinois Roscoe, Illinois Machesney Park, Illinois Loves Park, Illinois Rockford, Illinois Byron, Illinois Oregon, Illinois Grand Detour, Illinois Dixon, Illinois Sterling, Illinois Rock Falls, Illinois Lyndon, Illinois Prophetstown, Illinois Erie, Illinois Hillsdale, Illinois Cleveland, Illinois Colona, Illinois Moline, Illinois Coal Valley, Illinois Milan, Illinois Rock Island, Illinois See also Wikimedia Commons has media related to Rock River ( Illinois - Wisconsin ). List of Illinois rivers List of Wisconsin rivers References Jump up ^ U.S. Geological Survey. National Hydrography Dataset high - resolution flowline data. The National Map, accessed May 13, 2011 Jump up ^ U.S. Geological Survey Geographic Names Information System : Rock River Jump up ^ `` Castle Rock State Park ''. Illinois DNR. Retrieved 2014 - 08 - 03. Jump up ^ http://dnr.wi.gov/water/basin/uprock Jump up ^ `` Upper Rock River Basin - WDNR ''. Dnr.wi.gov. Retrieved 2016 - 02 - 03. Jump up ^ City of Dixon. `` Reagan 's Roots ''. Jump up ^ Channel 3000. `` Interstate 94, Highway 151 Reopen As Water Recedes ''. Channel 3000. Retrieved 3 February 2016. Jump up ^ `` Dam Information ''. Rock River Trail. Retrieved 22 April 2014. Jump up ^ `` Rock River Dams ''. PaddleAway. Retrieved 22 April 2014. Jump up ^ `` Dodge County, Wisconsin : Rock River Water Trail ''. Retrieved 3 February 2016. Jump up ^ `` Welcome to Jefferson County, Wisconsin ''. Retrieved 3 February 2016. External links Rock River Trail Retrieved from `` https://en.wikipedia.org/w/index.php?title=Rock_River_(Mississippi_River)&oldid=804270856 '' Categories : Rivers of Illinois Rivers of Wisconsin Tributaries of the Mississippi River Rivers of Dodge County, Wisconsin Rivers of Jefferson County, Wisconsin Bodies of water of Rock County, Wisconsin Bodies of water of Winnebago County, Illinois Rivers of Ogle County, Illinois Bodies of water of Lee County, Illinois Bodies of water of Whiteside County, Illinois Bodies of water of Rock Island County, Illinois Hidden categories : Coordinates on Wikidata No local image but image on Wikidata Lists of coordinates Geographic coordinate lists Articles with Geo All articles with failed verification Articles with failed verification from June 2014 Talk Contents About Wikipedia Wikivoyage تۆرکجه Cebuano Deutsch Français Frysk Italiano Nederlands 日本 語 Polski Português 中文 Edit links This page was last edited on 7 October 2017, at 21 : 59. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: where is the origin of the rock river
Answer: Horicon Marsh