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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

U.S. 12 Michigan to Washington

by Richard F. Weingroff

The U.S. numbering plan was developed in the mid-1920's by the U.S. Bureau of Public Roads and the State highway agencies. The Joint Board on Interstate Highways, consisting of Federal and State highways officials, developed the numbering plan in 1925. The plan was as follows: East-west routes were assigned even numbers, with the transcontinental or major east-west routes receiving numbers ending in "0." North-south routes were assigned odd numbers, with the main routes receiving numbers ending in "1" or "5." Other routes were assigned numbers within the grid established by the main routes. In addition, branches off the main roads were assigned three-digit numbers in sequential order (for example, the first branch of U.S. 40 would be U.S. 140, the second would be U.S. 240).

The Joint Board's tentative numbering plan, released in November 1925, included U.S. 12, described as follows:

From Detroit, Michigan, to Saginaw, Ludington, Manitowac, Wisconsin, Stevens Point, Neillsville, Ellsworth, Minneapolis, Minnesota, Wilbur, Ortonville, Milbank, South Dakota, Selby, Lemmon, North Dakota, Miles City, Montana. (Spelling as in the original)

Much of this routing, although not all of it, followed the Yellowstone Trail (Boston to Seattle), one of the prominent named trails of its day. Typically, the Joint Board avoided following any of the lengthy named trails through its entire mileage. The goal was to eliminate such trails; giving them a single number would encourage their backing organizations to continue their promotional efforts.

The Joint Board's numbering proposal was submitted to the American Association of State Highway Officials (AASHO) for adoption because the State highway agencies owned the roads. Over the next year, AASHO approved many changes in the numbering, often at the instigation of the named trails associations. Officials from cities left off a U.S. route or off a prominent route also lobbied their State highway officials to secure better placement on a "number" that was seen as providing economic opportunity.

On November 11, 1926, the State highway agencies, acting through AASHO, adopted the plan, including U.S. 12. The official log of the route was as follows:

United States Highway No. 12
Total Mileage, 1,301

Michigan Beginning at Detroit via Ann Arbor, Jackson, Marshall, Battle Creek, Kalamazoo, St. Joseph to the Michigan-Indiana State line east of Grand Beach.
Indiana Beginning at the Michigan-Indiana State line southwest of Grand Beach via Michigan City, Gary to the Indiana-Illinois State line at Hammond.
Illinois Beginning at the Indiana-Illinois State line west of Hammond via Chicago, Barrington to a point north of Algonquin and north to the Illinois-Wisconsin State line south of Genoa City.
Wisconsin beginning at the Illinois-Wisconsin State line south of Genoa City via Lake Geneva, Elkhorn, Whitewater, Fort Atkinson, Madison, Sauk City, Baraboo, Mauston, New Lisbon, Tomah, Black River Falls, Humbird, Augusta, Eau Claire, Minomonie to Hudson on the Wisconsin-Minnesota State line.
Minnesota Minneapolis, Litchfield, Willmar, Benson to the Minnesota-South Dakota State line west of Ortonville.
South Dakota Beginning at the Minnesota-South Dakota State line west of Ortonville via Wilbank, Summit, Aberdeen, Selby, Mobridge, McLaughlin, McIntosh to the South Dakota-North Dakota State line east of Lemmon.
North Dakota Beginning at the South Dakota-North Dakota State line east of Lemmon via Hettinger, Bowman to the North Dakota-Montana State line west of Marmarth.
Montana Beginning at the North Dakota-Montana State line west of Marmarth via Baker, Westmore to Miles City.

In addition, U.S. 12 had two branches, U.S. 112 and U.S. 212. The routing of U.S. 112 (156 miles) was as follows:

Michigan Beginning at Detroit via Ypsilanti, Clinton, Somerset, Jonesville, Coldwater, Sturgis, White Pigeon to the Michigan-State line north of Elkhart.
Indiana Beginning at the Michigan-Indiana State line north of Elkhart to Elkhart.

U.S. 112 would play an important part in the history of U.S. 12 several decades later.

This first official routing of U.S. 12 followed portions of several named trails. From Detroit to Kalamazoo, U.S. 12 used the routing of the Detroit-Lincoln-Denver Highway. In Indiana, it was the Dunes Highway. From the Wisconsin State line to Wilton, U.S. 12 was the Black and Yellow Trail (Chicago to Yellowstone National Park), picking up the Yellowstone Trail at Eau Claire. However, it soon departed the Yellowstone and followed the Glacier Trail from Minneapolis to Benson, Minnesota. Near Holloway, U.S. 12 returned to the Yellowstone Trail and stayed on it to McLaughlin, South Dakota. The Yellowstone Trail and U.S. 12 followed the same alignment through North Dakota to Westmore, Montana.

The Yellowstone Trail had originated in a 1912 meeting called by good roads enthusiast Joe W. Parmley of Edmunds County, South Dakota. Originally called the Twin Cities, Aberdeen and Yellowstone Park Trail, it was eventually extended east to Plymouth, Massachusetts, and west to Seattle Washington. It adopted the slogan "A Good Road from Plymouth Rock to Puget Sound." Two recent books cover the history of the Yellowstone Trail:

Meeks, Harold A., On the Road to Yellowstone: The Yellowstone Trail and American Highways 1900-1930, Pictorial Histories Publishing Company, Inc., 1920.

Ridge, Alice A. and John Wm., Introducing The Yellowstone Trail: A Good Road from Plymouth Rock to Puget Sound, Yellowstone Trail Publishers, 2000.

After the State highway agencies approved the numbering plan in November 1926, they controlled it through their national organization, the American Association of State Highway Officials (AASHO). All numbering requests (such as designation of routes, changes in existing numbered routes, or deletion of routes) were submitted by the State highway agencies to AASHO and its successor, the American Association of State Highway and Transportation Officials, for review and action.

By 1939, AASHO had approved a request from Montana and Wyoming to extend U.S. 12 from Miles City to Mammoth Hot Springs, Wyoming (Yellowstone National Park) via Forsyth, Hysham, Billings, Laurel, Rockvale, Red Lodge, and Cook City, Montana. This routing lasted until October 1959, when AASHO approved a relocation of U.S. 12 in Montana:

This routing would follow State Route 6 westerly from Forsyth via Melstone, Roundup, Ryegate, Harlowton and White Sulpher Springs to Townsend, thence northwesterly with U.S. 10N via Helena to Garrison, thence westerly with U.S. 10 via Drummond to Missoula.

A footnote to this action in the AASHO minutes indicated that before acting on Montana's request, the Route Numbering Committee checked with Idaho and Washington to determine that plans were underway to upgrade an extension of U.S. 12 via roads that would meet the standards and traffic needs of U.S. highways.

In 1962, Montana, Idaho, Washington, and Oregon proposed extending U.S. 12. On June 19, AASHO approved the extension to Lewiston, Idaho:

Beginning at western terminus of US 12 in Missoula, thence southwesterly over US 93 to Lolo, then westerly over State Route via Lolo Hot Springs to the Montana-Idaho State line at Lolo Pass.

Beginning at the Idaho-Montana State line at Lolo Pass thence southwesterly, westerly and northwesterly over State Route 9 via Lowell, Kooskia, Kamiah, Orofino, and Myrtle to US 95 at Spalding, thence westerly over US 95 to US 410 in Lewiston.

The extension was denied for the remainder of the route without explanation. In Washington, the route would have followed a line via Clarkston, Pomeroy, Walla Walla, Pasco, Kennewick, Roosevelt, and the Dalles to Vancouver. The application from Oregon indicated the U.S. 12 extension would turn southwest at Wallula, Washington, then continue via Cold Spring, Umatilla, and Irrigon to a point east of Boardman, Oregon. In other words, the two States had not agreed on the routing or terminus.

Later that year, when the AASHO Route Numbering Committee again considered applications from the two States for the extension west of Lewiston, the reason for rejection was explained in the minutes:

For the reason that the standards are inadequate and that it had been previously rejected on the same grounds, with no additional information showing change in the standards in effect on the section in question.

The Oregon section was rejected for a different reason:

For the reason that there is no agreement between the two States involved, which will permit a continuous routing and for the further reason that the matter had been rejected previously.

It is not clear why the two States submitted applications for an extension with different routing and termini. However, Idaho and Washington submitted the extension again in 1963, and it was again disapproved. In this round, the Washington segment ended in Pasco. The minutes do not contain an explanation, but presumably the reasons were the same as in the past.

The extension through Idaho and into Washington was finally approved on June 20, 1967. The extension was described as follows:

Beginning at the interchange with present US Routes 12, 95 and 410 in northeast Lewiston, thence southerly over present US Route 410 across the Clearwater River Bridge into Lewiston, thence in a north-westerly direction to the Idaho-Washington State Line.

Beginning at the Washington-Idaho State Line at Clarkston, thence westerly over present US Route 410 via Pomeroy, Walla Walla, Pasco, Richland, Prosser, Grandview, Sunnyside, Granger, and Zillah, to junction at Union Gap with US Route 97 thence continue north on US Route 410 through Yakima and Naches to junction with State Route 14 northwest of Naches, thence westerly over SR 14 via Rimrock, Packwood, Randle, Kosmos, Riffe, Mossyrock, Salkum, Ethel and Marys Corner to interchange US Route 99 (Interstate Route 5) south of Chehalis, thence north over US 88 (I'5) via Chehalis and Centralia to interchange with State Route 8 near Grand Mound, thence northwest on SR 8 via Rochester, Oakville and Malone to junction with US Route 410 at Elma, thence westerly over US Route 410 via Montesano to junction with US Route 101 in Aberdeen.

Aberdeen remains the western terminus of U.S. 12

Over the years, AASHO and AASHTO have approved routing variations within the Detroit-to-Aberdeen termini. These changes usually reflect the completion of improved roads for interstate traffic. One of the more significant changes occurred in Michigan. The original routing of U.S. 12 in Michigan was eventually followed by I-94. After I-94 opened, U.S. 12 was shifted onto I-94 across the State. However, in June 1961, AASHO approved a request from the State to relocate U.S. 12 onto a separate alignment:

This routing will be over former U.S. 112 from junction of present U.S. 12 and U.S. 112 east of New Buffalo to Ypsilanti, thence over present U.S. 12 by-passing Ypsilanti on the south to junction of former U.S. 112, thence over former U.S. 112 easterly to function with present U.S. 12 in downtown Detroit.

At the same time, AASHO approved the request for complete elimination of U.S. 112, a route that had paralleled U.S. 12 from the start of the U.S. highway system. The shift placed U.S. 12 onto the historic alignment of the Sauk Trail and the Chicago Road.

At the time of the most recent official log of U.S. numbered highways (1989), U.S. 12 was listed as 2,491 miles.