US 101 has some lovely historic bridges, many designed by the legendary Conde B. McCullough. From north to south, they are:
Interstate span across the Columbia.
More at Google Image Search, and
Concrete deck girder bridge with ocean far below and Neahkahnie Mountain cliffs far above. Designed by Glenn S. Paxson and built in 1937.
More at HistoricBridges.org and Google Image Search.
Early linked span bridge in Tillamook. Designed by Conde B. McCullough, in a much different style than that for which he is famous, but lovely nonetheless. Built in 1931, it's earlier than some of his iconic stone arches.
More at Google Image Search.
Modern flat concrete span, replaced older steel girder (drawbridge?).
Early (1921) Conde B. McCullough design, a relatively tiny span over a wave-churned channel to "the world's smallest navigable harbor." Don't miss the pedestrian underpass beneath the north end!
More at Google Image Search.
Where OR 182 meets US 101 near Rocky Creek Wayside, there are some nice turnouts with scenic cliff-top views. Just to the south on OR 182 is the Ben Jones Bridge, a picturesque and historic concrete span over Rocky Creek's dramatic plunge toward the ocean. Trees and shrubs cling to steep slopes, rocky cliffs endure crashing waves in the cove below. A small parking area just south of the bridge offers views and interpretive signage. Conde B. McCullough, 1927. Milepost 129 on US 101.
More at Bridgehunter.com, Wikipedia, Google Image Search, and Google Maps.
Conde B. McCullough arch bridge, 1936. Milepost 141 on US 101.
More at Google Image Search.
Simple, modern-looking span built c.1991. It replaced a historic Conde B. McCullough design that had been built in 1936. Milepost 155 on US 101.
More at Google Image Search.
Looks like a Conde B. McCullough design. It crosses Cape Creek near the Heceta Head Light. Milepost 178 on US 101.
More at Google Image Search.
Looks like a Conde B. McCullough design. It crosses the Siuslaw River at Florence. milepost 191 on US 101 is actually on the bridge.
More at Google Image Search.
Can't remember.
Conde B. McCullough arch bridge over Coos Bay, named in his honor. Milepost 234 on US 101.
More at Google Image Search.
Utilitarian steel two-lane structure; 40MPH.
Conde B. McCullough designed concrete arch bridge over the Rogue River between Wedderburn and Gold Beach. Begun 1930; opened 1932.
Steel girder bridge, highest bridge in Oregon.