20th century Starting in 1918, the Wisconsin Highway Commission erected highway numbers along state-maintained roadways. The highway across the state from
St. Croix Falls to
Armstrong Creek was numbered
WIS 14 at that time. The remainder of what is now US 8 was unnumbered secondary highways, and WIS 14 continued north of Armstrong Creek to
Florence. When Michigan numbered its highway system the following year, In Minnesota, US 8 would follow what was Constitutional Route 46, which was designated in a state constitutional amendment adopted on November 2, 1920; The first changes to the routings of the predecessor highways were made by Wisconsin by 1920. A series of curves were added between Turtle Lake and Barron adding "stair steps" to the routing while similar jogs were removed near Cameron, Weyerhauser, Hawkins and Prentice. WIS 14 was rerouted between Rhinelander and
Pelican Lake to run via
Monico, and
WIS 38 (the future US 141) was extended northward from
Wausaukee to terminate at the state line near
Niagara. The realignment between Rhinelander and Pelican Lake was shown as reversed by 1922. By 1925, the highway in that area was again rerouted to run directly from Rhinelander to Monico, but instead of turning south to Pelican Lake, it was run directly to Crandon. That same year, WIS 14 was extended eastward from Armstrong Creek to Pembine and northward to Niagara. The north–south section, previously numbered WIS 38, was also redesignated as part of
WIS 57. US 8 was created with the beginnings of the
United States Numbered Highway System on November 26, 1926. The highway was originally shown on maps running between
Forest Lake, Minnesota and
Powers, Michigan. At the time, its planned routing was not previously designated as part of the
State Trunkline Highway System in Michigan. The trunkline connection from
Quinnesec south into Wisconsin was part of
M-57, which met WIS 57 at the state line. US 8 ended at WIS 57 in Pembine at the time, with no connection into Michigan shown on official maps. A map by the
American Automobile Association does show the highway continuing east through
Faithorn and
Hermansville in Michigan to end at US 2. The Wisconsin Highway Commission previously indicated an unnumbered state highway on their 1925 state map that connected Pembine with the Menominee River near Hermansville. By the next year, the highway was shifted to end in Norway, utilizing a separate crossing of the Menominee River to enter Michigan. In 1931, US 8 was extended south from Forest Lake into downtown
Minneapolis. West of the Rhinelander area, US 8 and US 51 overlapped for about as US 8 jogged northward along US 51. This concurrency was altered in 1934, and two years later the short east–west section of US 8/US 51 was removed when changes to US 51's routing were finished in the area. A jog in the routing near
Almena was removed in 1937 when Wisconsin rerouted the highway to a more direct alignment in the area. the highway in Minnesota was paved in its entirety by 1940. Near Hawkins, a pair of sharp curves near the Rusk–Price county line were removed as the State Highway Commission realigned the highway to follow a straighter course. The US 8/US 51 concurrency was altered the next year to a shorter overlap running southward near
Heafford Junction. The former routing of US 8 was redesignated County Trunk Highway K (CTH-K) after it was transferred back to county control. Starting around the year 1955, US 8 was moved to a more direct routing between Forest Lake and Chisago City; US 8 replaced
MN 98 along Legislative Route 98. The former routing between Wyoming and Chisago City along Constitutional Route 46 was then redesignated MN 98 until it was
decommissioned in the late 1990s. As late as 1959, the
Michigan State Highway Department still had plans to build the section of US 8 west of Hermansville to the
Menominee River. The control section atlas published on January 1, 1959, showed this segment of highway on the
Menominee County map, complete with a control section number. The section of highway is shown as "proposed" or "under construction". However, a new bridge was built over the Menominee River to carry the highway across the Michigan–Wisconsin state line near Norway in 1966. WisDOT still shows the section of highway needed in their state to extend US 8 to the original eastern terminus in Michigan on internal maps. The December 31, 2004, edition of their
Official State Trunk Highway System Maps shows this section as a "mapped corridor". In the late 1970s, with ongoing construction and completion of the
I-35W freeway in Minnesota, US 8 was routed along I-35W; US 8 was truncated again by 1981 to its current terminus in Forest Lake. The section in
New Brighton is currently known as Old Highway 8. WisDOT built a bypass of the city of Rhinelander during the early 1990s; the new highway was constructed south of town as a new two-lane highway that opened to traffic by 1993. The former route through downtown Rhinelander and near Clear and George lakes was redesignated as
Business US 8 (Bus. US 8).
21st century In 2002, US 8 was widened from two lanes to four lanes with a grass median between North Rifle Road and
WIS 47 near Rhinelander, Wisconsin. At the time, officials with WisDOT had plans to extend the four-lane divided highway as far west as
US 51 near
Tomahawk. Problems related to wetlands in the construction area and bad weather pushed completion of the project back almost a year. Contractors had to install metal sheeting to stabilize the marshy ground. Originally scheduled to end in late 2002, the project did not finish until August 2003. The delays and additional work increased the price tag of the project from the original $4.5 million (equivalent to $ in ) to $6.0 million (equivalent to $ in ). A section of the project was only designed for speeds for safety reasons. The design also allowed planners to limit the amount of land needed for the expansion. Bill and Jerri Osberg sued the state and seven other parties in April 2003 over runoff from the construction, claiming that it killed hundreds of trees and polluted ponds on their property. Later investigation uncovered damage to wildlife habitat in the
Wisconsin River. Included in the original lawsuit were six individual WisDOT employees, the primary contractor and a local pet supply company. The court of appeals partially upheld a ruling by the district court dismissing the employees and the contractor from the lawsuit in March 2006. The pet supply company was reinstated in the case by the appeals court. The couple settled their claims, and the state pursued the matter against Pagel Construction in a related lawsuit. WisDOT alleged that the contractor did not follow proper erosion controls and failed to remediate the erosion damage to the Osbergs' property. The state wanted the construction company to forfeit their $70,000 retainer (equivalent to $ in ) and pay damages of $150,000 (equivalent to $ in ). Pagel Construction faulted WisDOT's erosion control plan and said that the state's engineers controlled the project and was seeking the return of its retainer. In September 2007, a jury ruled in favor of Pagel Construction and awarded them $70,898.13 in damages (equivalent to $ in ).--> == Future ==