What is Interstate 39?
{{Infobox road |country=USA |type=I |route=39 |map_notes=I-39 highlighted in red |length_mi=306.14 |length_ref=<ref name=fhwa>{{cite web |author= [[Federal Highway Administration]] |url= http://www.fhwa.dot.gov/reports/routefinder/table1.htm |title= Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of October 31, 2002 |date= October 31, 2002 |accessdate= March 28, 2007 |work= Route Log and Finder List |publisher= Federal Highway Administration }}</ref> |maint=[[Illinois Department of Transportation|IDOT]] and [[Wisconsin Department of Transportation|WisDOT]] |established= |direction_a=South |terminus_a={{Jct|state=IL|I|55|I|74|US|51}} in [[Normal, Illinois|Normal, IL]] |junction=<!-- Major junctions only; Only 5-8 most major intersections and cities belong here; please read [[WP:USRD/STDS]] for more info -->{{plainlist|1= *{{Jct|state=IL|I|80}} in [[LaSalle, Illinois|LaSalle, IL]] *{{Jct|state=IL|I-Toll|88|CKC}} in [[Rochelle, Illinois|Rochelle, IL]] *{{Jct|state=IL|I-Toll|90}} in [[Rockford, Illinois|Rockford, IL]] *{{Jct|state=WI|I|43|WI|81}} in [[Beloit, Wisconsin|Beloit, WI]] *{{Jct|state=WI|I|94|WI|30}} in [[Madison, Wisconsin|Madison, WI]]* {{Jct|state=WI|I|90|I|94|WI|78}} in [[Portage, Wisconsin|Portage, WI]] }} |direction_b=North |terminus_b={{Jct|state=WI|US|51|WI|29}} in [[Rothschild, Wisconsin|Rothschild, WI]] |states=[[Illinois]], [[Wisconsin]] |counties='''IL''': [[McLean County, Illinois|McLean]], [[Woodford County, Illinois|Woodford]], [[Marshall County, Illinois|Marshall]], [[LaSalle County, Illinois|LaSalle]], [[Lee County, Illinois|Lee]], [[Ogle County, Illinois|Ogle]], [[Winnebago County, Illinois|Winnebago]]<br/>'''WI''': [[Rock County, Wisconsin|Rock]], [[Dane County, Wisconsin|Dane]], [[Columbia County, Wisconsin|Columbia]], [[Marquette County, Wisconsin|Marquette]], [[Waushara County, Wisconsin|Waushara]], [[Portage County, Wisconsin|Portage]], [[Marathon County, Wisconsin|Marathon]] |browse={{infobox road/browselinks/USA|state=IL}}{{info