One of the more interesting highways I drove recently this past month was CA 45 along the Sacramento River. CA 45 essentially is the middle ground between I-5 and CA 99 but is definitely far more rural in character. The southern segment of CA 45 from CA 113 to CA 20 resembles an early era State Highway with various 90 degree farm-land turns. Probably the most interesting aspect of CA 45 is that it existed in two sections until 1959 when a gap between Colusa and Glenn was turned over to State Maintenance. There are some interesting sites on CA 45 to see such as; the Grand Island Shrine, Sutter Buttes and Colusa County Courthouse.
https://surewhynotnow.blogspot.com/2019/02/california-state-route-45.html
My photo set for CA 45 can be found below:
https://flic.kr/s/aHsmAD8sS3