  right|300px|thumb|the golden gate the golden gate is the north american strait that connects san francisco bay to the pacific ocean. it is defined by the headlands of the san francisco peninsula and the marin peninsula, and, since 1937, has been spanned by the golden gate bridge. ==geology== during the last ice age, when sea level was several hundred feet lower, the waters of the glacier-fed sacramento river and the san joaquin river scoured a deep channel through the bedrock on their way to the ocean.a similar process created the undersea hudson canyon off the coast of new york and new jersey. the strait is well known today for its depth and powerful tidal currents from the pacific ocean. many small whirlpools and eddies can form in its waters. with its strong currents, rocky reefs and fog, the golden gate is the site of over 100 shipwrecks. ==climate==  the golden gate is often shrouded in fog, especially during the summer. heat generated in the california central valley causes air there to rise, creating a low pressure area that pulls in cool, moist air from over the pacific ocean. the golden gate forms the largest break in the hills of the california coast range, allowing a persistent, dense stream of fog to enter the bay there. ==history==  before the europeans arrived in the 18th century, the area around the strait and the bay was inhabited by the ohlone to the south and coast miwok people to the north. descendants of both tribes remain in the area.  the strait was surprisingly elusive for early european explorers, presumably due to this persistent summer fog. the strait is not recorded in the voyages of juan rodriguez cabrillo nor francis drake, both of whom may have explored the nearby coast in the 16th century in search of the fabled northwest passage. the strait is also unrecord
Landforms_of_Marin_County,_California Landforms_of_San_Francisco,_California San_Francisco_Bay Straits_of_California