State Route 65 was added to the state highway system in 1931, following the historic
Mormon Trail as closely as practicable from
SR-5 (
US-30S, now
I-84) in
Henefer over
Big Mountain Pass and through
Emigration Canyon to
Salt Lake City (later meeting
SR-186 there). The portion of SR-65 east of
Mountain Dell was removed from the route in 1945 in favor of a connection with
SR-4 (
US-40, now
I-80) in
Parley's Canyon. (The connecting
SR-66 was truncated at the same time, and has since been reconnected.) Two years later, this law was essentially repealed, as SR-65 was moved back to the full Henefer-Salt Lake City route; the connection to SR-4 became a new
State Route 239. Roads within
This Is The Place Monument near the west end were also added to the route for the state to maintain. The state legislature removed the western portion in 1969, rerouting SR-65 to its current alignment between I-80 in Parley's Canyon and I-84 in Henefer and replacing SR-239. However, at the same time,
SR-3 (which had replaced SR-5) was moved to I-84, and the old route through Henefer became an extension of SR-65 - in both directions. The western connection to I-84 was renumbered
State Route 86 in 1975. ==Major intersections==