Petrolia is located near the
Mendocino triple junction, where three geologic
fault lines meet, and experiences frequent earthquake activity. A
magnitude 7.1
earthquake in 1992 resulted in a fire that destroyed the 100-year-old Petrolia General Store. Two of the remaining landmarks in Petrolia are a small wooden church dating from 1912—St. Patrick's Catholic Church—and the Petrolia Pioneer Cemetery, which has the graves of original residents of Petrolia dating from November 1857. On the evening of March 9, 2014, a magnitude 6.9 earthquake struck approximately 50 miles to the west. It was widely felt, yet caused little to no damage, nor did it generate a tsunami. The lack of any significant damage or land deformation was attributed to the shallow strike-slip fault movement in deep (3000m) water. In 2010 two other large quakes had hit the area, a 6.5 on January 9 and a 5.9 on February 3; neither caused any deaths, but the January quake was reported to have caused damage throughout the area. The weather in Petrolia is temperate. The town is located in a area that is sheltered from the fog that reaches Eureka and some of the northern towns, such as
Arcata and
McKinleyville. As a result, the summers are dry and sunny, typically around with temperatures occasionally reaching as high as . Winters are rainy from November through April, with temperatures typically around and occasionally falling to the high 30s or low 40s (°F) at night.
Honeydew, California, which is located only south of Petrolia, has a less temperate climate and its summers and winters are more extreme, with one of the highest amounts of winter rainfall in the contiguous 48 states. There are only two roads that lead into Petrolia, one from the north from
Ferndale, California, and one from the south from Honeydew, leading through scenic redwood forests that were the site for the filming of
Jurassic Park and
After Earth. Both roads are winding, steep, and sometimes unpaved, passing large tracts of scenic overlooks and wilderness areas. They are popular routes for visitors, especially mountain bikers and motorcyclists, and have been described as leading to "an almost comically steep drop to the sea". The road from Petrolia to Ferndale follows the ocean and has unbroken vistas of rocky ocean coastline and beach. ==History==