Puget Sound faults about 1100 years ago (AD 900—930) an earthquake of magnitude 7+ uplifted Restoration Point and Alki Point, dropped West Point (the three white triangles in the Seattle Basin on the map), caused rockslides in the Olympics, landslides into Lake Washington, and a tsunami on Puget Sound. It extends as far east as (and probably terminates at) the Rattlesnake Mountain Fault Zone (RMFZ; the southern extension of the SWIF) near Fall City. This seems geologically reasonable, as both the SWIF and RMFZ appear to be the contact between Tertiary Crescent Formation basement of Puget Sound on the west and the older
Puget Sound but increases to about at Olympia, the southern end of Puget Sound. Puget Sound is generally accepted as the start of the Inside Passage. Important marine flora of Puget Sound include eelgrass ("Zostera marina") and kelp, especially bull kelp ("Nereocystis luetkeana"). Among the marine mammals species found in Puget Sound are harbor seals ("Phoca vitulina"). Orca ("Orcinus orca") are famous throughout the Sound, and are a large tourist attraction. Although orca are sometimes seen in Puget Sound proper they are far more prevalent around the San Juan Islands north of Puget Sound. Many fish species occur in Puget Sound. The