(Junction City to Eugene)
OR-54 (1926-1940); US-20 (1940-1952)
North Fork Siuslaw Rd. (Siuslaw County Road 5070)
(Florence to Brickerville)
(Brickerville to Junction City)
(within Junction City)
E 1st. Ave, River Rd., Railroad Ave., Van Buren St., Blair Blvd.
Willamette St., Broadway
(Eugene to Springfield)
(Springfield to Belknap Springs; Sisters to Prineville)
(Belknap Springs to Sisters)
(Prineville to Vale)
(Vale to Cairo Jct.)
(Cairo Jct. to Ontario)
US-28 was created at the inception of the US Highway system in 1926 and lasted until 1952, when it was replaced by US-26 and US-126 along what was left of the original routing. Its original full routing was between Florence and Ontario, Oregon's only major US route that was always only within the state. The other interesting note is that it was always south of US-30, making it an anomaly in the current US highway numbering scheme; however, when a 1925 USDA BPR report was released making recommendations about US highway numbers, US-30 was numbered as US-20, so the US-28 numbering was probably a hold-over from that.
The original routing of US-28 between Florence and Eugene lies mostly along what is now OR-36, with a multiplex with current OR-99 into Eugene, However, US-28 also ran along a Siuslaw County Road, the North Form Siuslaw Rd., was changed to OR-36 when US-28's western terminus was truncated to Eugene in 1936. From then on, US-28 ran along what is now OR-126 Business, OR-126, OR-242, US-26, US-20, and OR-201 to Eugene where it met up with old US-30 (current US-30 Business). In 1952, when US-26 was extended into Oregon from Wyoming, US-28 became OR-201 from Ontario to Cairo Jct., US-26 from Cairo Jct. to Prineville, and US-126 from Prineville to Eugene; US-28 was retired.
There are many former alignments of US-28, with one of the oldest alignments following the North Fork of the Siuslaw River (shown in red). When US-28 was first signed, the alignment bypassed Mapleton, veering instead towards the small unincorporated towns of Linnaeus and Minerva deep in the Siuslaw National Forest. It is unclear if this alignment was bypassed while US-28's western terminus was in Florence; my guess is that this segment was replaced by the modern alignment around the time that OR-36 was extended to Florence and US-28 was truncated to Eugene. This alignment lives on as the North Fork Siuslaw Rd., also known as Siuslaw County Route 5070.
The second alignment runs from Junction City to Eugene. This routing, shown in green, started at the junction of current OR-99 and E 1st Ave. in Junction City, with US-28 following the old US-99 down E 1st Ave. This road eventually becomes River Road, which continues into Eugene. Then, the route jogs left on Railroad Ave., crosses the railroad tracks on Van Buren St., and then veers left onto Blair Blvd. before rejoining current OR-99 at Sixth Ave. A word of warning: Sixth Ave. is now a one-way street, so following the old US-28 route requires you to turn left onto Seventh Ave.
There also is a slight rerouting of US-28/US-99 through Eugene. While the current OR-99 and a later alignment of US-99 follows Sixth and Seventh before slightly moving towards Broadway and Franklin by hooking into the Coburg Rd. Bridge, the former alignment went down Willamette St. until Broadway; there, it took a left and proceeded down Broadway until reconnecting with the current alignment. A one-block portion of Willamette St., between Sixth and Seventh Aves., no longer exists, however.
These are some of the many alignments of US-28 (and possibly US-26). These alignments (shown in blue) were definitely a part of old US-28, but I am unsure of when they were bypassed by the current alignment, so they may have been used through US-28's decommissioning. In the ODOT logs, the first section is simply known as "Road," but the second and third sections are called the "Old Hwy." on maps; the third segment is also Mitchell's Main St.
When roads were initially built in Oregon, they usually followed alignments that were very curvy and dangerous at modern speeds. Many mountainous ones weren't paved or even covered with gravel. It was in this era that this alignment of US-28 (shown in purple) was built. I do not believe that it still is not paved, but its alignment is very windy with several sharp switchbacks, making it unsafe even for the 1950s. This alignment was never US-26; however, it still lives on as Grant County Road 72.
The final former alignment of US-28 that is intact is this section along the Grant-Baker County Line. This section, shown in turquoise, survives as National Forest Road 500, but is also called the Old Hwy. This was most likely bypassed to eliminate a sharp 180° turn along the highway. It is unknown if this route was ever US-26.