The morning of our launch brought near-perfect road trip weather: crystal clear skies, moderate temperatures (for Wisconsin) and no rain in the forecast. I topped off the Traverse’s gas tank, made the rounds to pick up my co-pilots/navigators Chuck Haynes and Matt Parish and headed for the Illinois/Wisconsin border to begin our journey.
Today, Highway 51 in Illinois piggybacks on Interstate 39 from Bloomington-Normal to the Wisconsin stateline where it gets off the freeway and follows its original alignment as it enters the Badger State. From here all the way to Portage, the highway mostly follows the same path it has since 1926 and, except for urban segments, is mostly two lane road. Oddly, 51 does jump back onto I-39 for a short three mile stretch between Edgerton and Stoughton but you can, instead, take its old alignment (Albion Road) which runs parallel to the freeway.
Portage is where the road trip gets interesting. At the north end of Portage, Highway 51 gets on I-39 once again and it remains a four-lane freeway until well past Tomahawk. (I-39 ends at Rib Mountain Road in Wausau but Highway 51 continues on as a freeway beyond that point.) Careful study of old highway maps shows that before there was a freeway, Highway 51 exited Portage on what is now designated County Road CX. You can take CX almost all the way to Packwaukee but broken connections require you to take a slight detour to get back to the point where 51 headed north out of Packwaukee on what is now County Road M.
Along this and most other stretches of Highway 51’s freeway profile, new sections were not built over top of older alignments but were, instead, plotted along completely new alignments. Older segments were left in place and redesignated as county trunk roads, making it possible for amateur “highway archeologists” to find the old routes and enjoy them. In fact, between Plainfield and Plover, Highway 51 used to run along the route that is now designated as County BB and the current four-lane section was built over top of the old County BB. U.S. 51 and County BB simply traded places along this 20 mile stretch.
Upgrades to Highway 51 in Wisconsin began in the early 1960s with the bypass around Wausau. Over time, similar bypasses were constructed at other points such as Portage and Stevens Point and those were later connected together by four-lane freeway, making the older two-lane segments obsolete. The up side for those of us who prefer the charm of a narrow country road is that those old routes are now the road-less-traveled with very little traffic and never any grid lock. Oh, and you hardly ever see a cop.
Next: Some Wisconsin history along Highway 51