An earlier road to Giant Forest, completed in 1903, quickly proved inadequate for increasing motor car use. Completion of a new road providing wider turns and less grade became a high priority, so a road survey of the Middle Fork Canyon was ordered in 1918. Following a zone of softer metamorphic rock, the road construction was still an arduous task. In 1926, visitors were able to travel the new highway from Ash Mountain to Giant Forest.
Despite its open appearance, the Middle Fork Canyon of the Kaweah River is nearly as deep as Arizona's Grand Canyon. The summit of Moro Rock is 4,000 vertical feet above the canyon floor, and east of here the canyon is even deeper. The steep terrain of this region made pioneer access extremely difficult. Only after the construction of the Generals Highway, 1921-1926, did Giant Forest become easily accessible.