Understand
Puget Sound is a sheltered arm of ocean between Seattle and the mainland of Washington State to the east and the Olympic Peninsula to the west. The southern boundary is marked by where the mainland and the Olympic Peninsula meet, near Tacoma. The northern boundary is marked by Admiralty Pass and the Strait of San Juan de Fuca.
The San Juan Islands are not properly located in Puget Sound, contrary to common belief and widespread usage. There has been a recent popular movement to officially name the area that contains the San Juan Islands as the Salish Sea, in honor of the native people of the region. The Salish Sea is located at the confluences of Puget Sound, Strait of Juan de Fuca, Strait of Georgia.
The Puget Sound region consists of Puget Sound itself, the islands of Puget Sound, the Kitsap Peninsula, plus the mainland counties which form both the western and eastern sides of Puget Sound leading up to the edges of the watershed in the high crests of the Cascade and Olympic mountain ranges. Counties with this area include: Island, Snohomish, Kitsap, King, Pierce, and Thurston