A road from Banning to Idyllwild was planned around the turn of the twentieth century, and was open by 1910.

SR 243 makes a left turn at the intersection with Circle Drive and continues through Pine Cove.

The road continues through the forest past Mount San Jacinto State Park through Twin Pines and the Morongo Indian Reservation before making a few switchbacks and descending en route to the city of Banning as the Banning Idyllwild Panoramic Highway.

[9] In 2013, SR 243 had an annual average daily traffic (AADT) of 1,650 between Marion Ridge Drive in Idyllwild and San Gorgonio Avenue in Banning, and 6,500 at the northern terminus in Banning, the latter of which was the highest AADT for the highway.

[12] The oiled road was completed by September 1910, and provided a view of Lake Elsinore and the Colorado Desert, and it was expected to help with transporting lumber and stopping fires; because of this, the federal government provided $2,000 for the construction.

Except where prefixed with a letter, postmiles were measured on the road as it was when the route was established, based on the alignment that existed at the time, and do not necessarily reflect current mileage.