This past October I was visiting Coachella Valley and was knocking as many highway alignments as a I could. Given the former route of CA 231 was just west of former CA 195 I decided to drive it's former 4 mile alignment via 66th Avenue from Pierce Street west to former US 99/CA 86 on Harrison Street in Valerie. The first CA 231 was added to the State Highway System in 1935 as Legislative Route 204. LRN 204 would be assigned CA 231 during the 1964 State Highway Renumbering. CA 231 would last long as it was deleted in 1972 but the route designation was briefly recycled in the late 1980s for a new toll road which later became in part CA 261, CA 133 and CA 241.
https://www.gribblenation.org/2019/11/former-california-state-route-231.html