US 97... in Alaska??

1867: The United States acquired Alaska from Russia, and it became a U.S. Territory.

1926: AASHO commissioned US 97; its northern terminus was (and still is) at the US-Canada border between Oroville WA and Osoyoos BC. 

1941: When Pearl Harbor was attacked, the U.S. was suddenly very motivated to build roads in Alaska, noting the importance of supply routes to her military installations there.  At the time, road building in Alaska was primarily under the direction of the U.S. Bureau of Public Roads (BPR), and the U.S. provided the funds to construct even the Canadian segments of the highway.

1953: British Columbia changed some of her route designations, including BC 97, which begins at the same border crossing as US 97 and continues northward along the Cariboo Highway to Prince George, and from there along the John Hart Highway to Dawson Creek.  At Dawson Creek, the BC 97 designation was applied to the Alaska Highway, continuing north all the way up to the boundary of Yukon Territory.  This action may have been encouraged by the Okanogan-Cariboo Trail Association (which billed their road as "the shortest route to Alaska" and would have advocated for the 97 designation along the entire highway).

1956: Once BC 97 had reached Yukon, it was easy for folks to imagine the "highway 97" designation extending further north and west through Yukon and crossing into Alaska, via the Alaska Highway to Delta Junction, and then the Richardson Highway to Fairbanks.  In Alaska, how should that route be designated?  Well, Alaska was not a state yet, so not "AK 97".  But it was a U.S. Territory, so why not "US 97"?

At that time, Alaska was not a member of AASHO, and AASHO had not yet been asked to approve the US 97 designation in Alaska.  So why did USGS maps show US 97 in Alaska?  Many of the features shown on USGS maps (especially during the 20th century) were sourced from field-checks.  So it seems quite likely that the reason USGS maps showed US 97 in Alaska was because US 97 signs were posted along the highway during the time that the cartographers field-checked their maps (refer to the 1956 paragraph, above).

1959: Alaska was admitted as the 49th state in the Union.  I suspect the US 97 signs were removed shortly thereafter, because USGS maps printed in 1960 and later were not labeled with US 97 shields.

1964: The recently-formed Alaska Dept. of Highways sent an application to AASHO formally requesting the US 97 designation in their state.  Why would Alaska want a US route?  They anticipated and answered that question in their application; following is an excerpt:

If AASHO had accepted Alaska's proposal, I imagine that US 97 initially would have been routed along S. Cushman up to Airport Way (until the current alignment of Richardson Hwy. was built).  During this same timeframe, the Okanogan-Cariboo Trail Assn. wrote a letter to Alaska DOH.  I have not seen the contents of that letter, but I am quite certain it was regarding the re-posting of US 97 shields in Alaska.  That is based on Alaska's reply to their letter, a portion of which is reproduced below:

AASHO's response later in 1964 was generally favorable, although tempered by the stipulation that Alaska could signpost its portion of the route as US 97 only if both BC and Yukon also designated their segments of the Alaska Highway with the number 97.  Since BC had already done this, AASHO was really referring to Yukon:

1968: Yukon Territory assigned numbers to its highways, but unfortunately they opted not to designate their segment of the Alaska Highway as Yukon 97 (instead they christened it Yukon Highway 1). Later that year, AASHO exchanged correspondence with Alaska Dept. of Highways, whose response included this paragraph:

Research and/or image credits: Jake Bear; Scott Broady; Tom Hamilton; Richard Hartweg; Michael Nore; Dale Sanderson; Ray Savella; Michael Summa; Jim Teresco; Roger Topp