[1] In addition, the steepness and related geotechnical challenges of the coastal mountains made this stretch of coastline too costly for state highway or county road builders to establish routes through the area, leaving it the most undeveloped and remote portion of the California coast.

[2] Without any major highways, communities in the Lost Coast region such as Petrolia, Shelter Cove, and Whitethorn are somewhat isolated from the rest of California.

Most of the region's coastline is now part of either Sinkyone Wilderness State Park or King Range National Conservation Area.

The Lost Coast includes Tertiary marine sedimentary formations north of the Mattole River and a portion of the Franciscan Assemblage called Point Delgada at Shelter Cove.

The King Range mountains collect significant moisture from storms coming from the Pacific Ocean, making it one of the wettest sections of the California coastline.

From May to September, the mountain areas are mostly warm and dry with temperatures reaching 80 °F (27 °C)–90 °F (32 °C) in mid-summer, but the weather is still highly variable, with some days of fog and light rain.

Steep terrain and unfavorable coastal mooring conditions delayed timber harvesting of Jackass Creek drainage until internal combustion machinery was available for transport.

In 1984, admitting that such construction was not feasible, Caltrans re-routed the northern segment of Highway 1 from Rockport to Leggett and renumbered the portion that was built from Ferndale to Fernbridge as State Route 211.

Without major highways or county thoroughfares in the area, the secluded communities within the Lost Coast are only accessible by land via small mountain roads.