The Lost Coast is a mostly natural and undeveloped area of the California North Coast in Humboldt and Mendocino Counties, which includes the King Range. It was named the "Lost Coast" after the area experienced depopulation in the 1930s. In addition, the steepness and related geotechnical challenges of the coastal mountains made this stretch o…The Lost Coast is a mostly natural and undeveloped area of the California North Coast in Humboldt and Mendocino Counties, which includes the King Range. It was named the "Lost Coast" after the area experienced depopulation in the 1930s. 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. 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.