Rex River

The Rex River is a river in the U.S. state of Washington. It originates near the crest of the Cascade Mountains and flows northwest to join the Cedar River in the Chester Morse Lake reservoir. The Cedar River flows to Lake Washington and, ultimately, Puget Sound. Tributaries of the Rex River include Pine Creek, Lindsay Creek, and Boulder Creek.

Rex River
Location of the mouth of the Rex River in Washington Show map of Washington (state) Rex River (the United States) Show map of the United States
Location
Country	United States
State	Washington
County	King
Physical characteristics
Source	Cascade Range
• coordinates	47°18′7″N 121°36′9″W[1]
Mouth	Cedar River
• location	Chester Morse Lake
• coordinates	47°22′43″N 121°41′48″W[1]
Basin size	13.4 sq mi (35 km2)[2]
Discharge
• location	river mile 3.0[2]
• average	100 cu ft/s (2.8 m3/s)[2]
• minimum	3.0 cu ft/s (0.085 m3/s)
• maximum	4,200 cu ft/s (120 m3/s)

The Rex River is entirely contained within the Cedar River Municipal Watershed, an area managed by the City of Seattle which provides two-thirds of the water supply for the greater Seattle metropolitan region.[3][4]