The western terminus of the western segment is at State Route 529 (Maple Street) in Everett, Washington. The eastern terminus of the eastern segment is at Interstate 95 in Houlton, Maine. The eastern terminus of the western segment is at Interstate 75 in St. Ignace, Michigan. The western terminus of the eastern segment is at U.S. Route 11 in Rouses Point, New York.
As its number indicates, it is the northernmost east-west U.S. Route in the country.
The Adventure Cycling Association's Northern Tier bicycle touring route follows or parallels US 2 for over 600 miles (965 km), most notably a 550 mile (885 km) stretch between Columbia Falls, Montana and Williston, North Dakota.
US 2 passes into Montana from Troy, a small city. It is also near the lowest point in Montana, where the Kootenai River leaves the state. The first large city the highway comes to is Libby. After this it meanders south and east towards Kalispell, a city of about 20,000 residents north of Flathead Lake, the largest freshwater lake west of the Mississippi River. From there the highway passes through the southern end of Glacier National Park and follows the Middle Fork of the Flathead River. After crossing the continental divide at Marias Pass west of East Glacier, the highway exits the Rocky Mountains and begins its trek through the northern plains. Just before entering East Glacier, it crosses the boundary of the Blackfeet Indian Reservation of northern Montana.
As the highway enters the Great Plains, the first town it encounters is Browning, the largest settlement on the Blackfeet Indian Reservation. From here to the North Dakota border, the surrounding area is also known as "The Hi-Line" to Montanans from the early GN railway route. It next travels through Cut Bank to Shelby, where it becomes the northern border of the area known as the "Golden Triangle" in Montana. This area is one of the most productive farming regions in the country. From Shelby it hits a string of small towns before it goes on to Havre, near the geographical center of the road in the state. Just south of Havre and off the highway about fifteen miles (24 km) is the Rocky Boy Indian Reservation. The highway continues east to Malta, before which it travels through the Fort Belknap Indian Reservation. From Malta, the highway continues on to Glasgow, just north of Fort Peck Dam, and then into the Fort Peck Indian Reservation. The highway stays within the reservation for much of its remaining trip through Montana. On the reservation it goes through Wolf Point and Poplar, and then exits the reservation a short distance before leaving the state. The final town of Bainville says goodbye to the highway as it leaves the state, near the confluence of the Missouri and Yellowstone Rivers.
US 2 intersects with two north-south four-lane highways in North Dakota: US 83 at Minot and Interstate 29 at Grand Forks. In addition, it junctions with two other US Highways that, except for shorter stretches that are four-laned, are mostly two-lane highways in North Dakota: US 85 at Williston and US 52 at Minot. All four of these highways provide routes either to the border at Mexico or deep into southern USA.
North Dakota has been converting sections of US 2 from two lanes to four lanes for many years. The section from Grand Forks to Minot was completed several years ago. The section from Minot to Williston was completed in the summer of 2008 in a campaign that began a few years ago and was labeled “Across the State in Two Thousand Eight”. Actually, US 2 is four-laned from North Dakota’s eastern edge to just past Williston, a stretch of about 343 miles, leaving the remaining 12 miles to the Montana border as a two-lane highway. North Dakota’s governor has said that North Dakota will four-lane the remaining stretch if Montana is willing to continue the four-laning project from the border into their state.
Between Williston and Minot, US 2 provides several high points where you can view graceful and beautiful landscape for many miles in all directions. Between Minot and Grand Forks, US 2 provides an ever changing mix of agricultural farm and pasture land, native wetlands, and small lakes set on a gently rolling landscape. US 2 also passes near a large lake near Devils Lake.
In Rugby, North Dakota, the highway passes the location designated in 1931 as the geographical center of North America. The monument marking the geographic center had to be relocated in 1971 when US 2 was converted from 2 lanes to 4 lanes.
Legally, the Minnesota section of U.S. 2 is defined as Routes 8 and 203 in Minnesota Statutes §§ 161.114(2) and 161.115(134).
Of the of US 2 in Minnesota, have four lanes, mostly located in the western part of the state.
The road starts up at U.S. Route 11, just one mile (1.6 km) south of the Canadian border near Champlain, New York. From there it crosses Lake Champlain into Grand Isle County, Vermont, traversing the length of the county and crossing the lake over several bridges until it reaches the mainland in Milton and Chittenden County. From there it travels south to Burlington, where it begins to closely parallel Interstate 89 all the way to Montpelier and Washington County. At Montpelier, the road turns north-eastward, crossing into Caledonia County and passing through Saint Johnsbury. It then passes into Essex County, and eventually crosses the Connecticut River from Guildhall, Vermont into Lancaster, New Hampshire.
A large portion of the western segment of US 2, and a shorter piece of the eastern segment, follows the old Theodore Roosevelt International Highway. This auto trail, named in honor of recently-deceased ex-president and naturalist Theodore Roosevelt, was organized in February 1919 to connect Portland, Maine with Portland, Oregon. The route taken by this highway left Portland, Maine to the northwest, crossing New England via Littleton and Montpelier to Burlington. It crossed Lake Champlain on the Burlington-Port Kent Ferry and headed west across upstate New York, through Watertown and Rochester to Buffalo. After crossing southern Ontario, the highway re-entered the U.S. in Detroit, running northwest and north via Saginaw and Alpena to the Upper Peninsula, where it turned west along the northern tier of the country. This portion took the route past Duluth, Minot, Havre, and Glacier National Park to Spokane. In order to reach Portland, Oregon, the highway turned south in Washington via Walla Walla to Pendleton, where it headed west again via the Columbia River Highway to Portland. The last piece of the highway to be completed was over Marias Pass through Glacier National Park; cars were carried through the park on the Great Northern Railway until 1930.
The first inter-state numbering for the Roosevelt Highway was in New England, where the New England road marking system was established in 1922. Route 18 followed the auto trail from Portland northwest to Montpelier, where it continued to Burlington via Route 14. Many of the states along the route also assigned numbers to the highway; for instance, New York labeled their portion Route 3 in 1924. The Joint Board on Interstate Highways distributed its preliminary plan in 1925, in which a long section of the highway was labeled US 2, from St. Ignace, Michigan west to Bonners Ferry, Idaho. East of St. Ignace, instead of crossing to the Lower Peninsula like the Roosevelt Highway, the proposed Route 2 traveled north to the international border at Sault Ste. Marie. It reappeared at Rouses Point, New York, following Route 30 and then rejoining the auto trail between Burlington and Montpelier. US 2 and the Roosevelt Highway both connected Montpelier to St. Johnsbury, but the latter took a direct path along Route 18, while the former was assigned to Route 25 to Wells River, where it overlapped proposed US 5 north to St. Johnsbury. There, where the Roosevelt Highway turned southeast to Portland, Route 2 continued east along Route 15 to Bangor and Route 1 to Calais, then heading north on Route 24 to end in Houlton.
By the time the U.S. Highway system was finalized in late 1926, one relatively minor change had been made to US 2; it was swapped with US 1 between Bangor and Houlton, Maine, placing US 2 along the entire portion of Route 15 east of St. Johnsbury. Several other major parts of the auto trail received numbers, most notably US 30 from Portland, Oregon east to Pendleton, US 195 in eastern Washington, and US 23 in Michigan's Lower Peninsula. In the mid-1930s, much of New York's portion of the road became US 104, and the part southeast of Littleton, New Hampshire to Portland, Maine became US 302, but by far the longest piece was that followed by US 2 between St. Ignace and Bonners Ferry.
US-2 originally ran in Michigan from Ironwood to St. Ignace, the same termini as today. The highway has undergone many realignments, mostly minor, between those cities since 1926. In 1948, the eastern terminus in Michigan was extended to Sault Ste. Marie along Mackinac Trail.
In 1957, the first segment opened of a new freeway between St. Ignace and Sault Ste. Marie. It ran from Evergreen Shores, north of St. Ignace, to present-day M-123 and replaced the former route on State St. and Mackinac Trail. Over the next six years, US-2 was moved from Mackinac Trail onto the new freeway as new sections opened. Beginning in 1961, the freeway was concurrently signed as an extension of I-75. The freeway was completed in 1963.
The eastern terminus of US-2 in Michigan was truncated back to St. Ignace in 1983, removing it entirely from the I-75 freeway.
Before being designated as US 2, most of the current alignment was called New England Interstate Route 15 from Danville, Vermont eastward to Maine. The portion of the old Route 15 that did not become part of US 2 was designated as Vermont Route 15.
Other sections of US 2 in Vermont that were not part of New England Route 15 were parts of other former New England Interstate routes: Route 18 between Montpelier and Danville; Route 14 between Burlington and Montpelier; and Route 30 between Alburgh and Burlington.