The route is a loop west off of U.S. Route 395 passing through the community of June Lake, following the watercourse of June Lake, Gull Lake, Reversed Creek, Silver Lake, Rush Creek and Grant Lake, into the Mono Basin. The highway provides access to several vacation areas, trailheads, and scenic locations, including the June Mountain ski and snowboard resort.
SR 158 from 3.5 miles (5.6 km) north of June Lake to the northern junction with U.S. Highway 395 is closed during winters, typically from mid-December through mid-April.
Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage. R reflects a realignment in the route since then, M indicates a second realignment, L refers an overlap due to a correction or change, and T indicates postmiles classified as temporary (for a full list of prefixes, see the list of postmile definitions). Segments that remain unconstructed or have been relinquished to local control may be omitted. The entire route is in Mono County.