Pacific Ocean expansion on each side of the East Pacific Rise commenced near Antarctica and moved north to intercept the Gulf of California. To the East of the Rise, expansion moved blocks in the Basin and Range terrain in the Rockies to accommodate expansion. To the West the Pacific Ocean expanded. The Rise backfilled the Central American Trench as it neared the coast, and expansion westwards widened the Ocean. The acute angle intercept is to the East and the obtuse intercept to the West. The rise intercepted the coast at the Gulf of California and became the San Andreas Fault as it extended north into California.