Pattison Lake

Pattison Lake
Pattinson Lake, viewing northwest, 2025
LocationThurston County, Washington
Coordinates46°59′43″N 122°46′39″W / 46.9952709°N 122.7775103°W / 46.9952709; -122.7775103
TypeLake
EtymologyJames Pattison
Basin countriesUnited States
Surface area257 acres (104 ha)
Max. depth20 feet (6.1 m)
Surface elevation161 ft (49 m)
ReferencesGeographic Names Information System: 1510726

Pattison Lake is a lake in the U.S. state of Washington. The lake has a surface area of 257 acres (104 ha), and reaches a depth of 20 feet (6.1 m). The lake was named after James Pattison, a pioneer settler.

In June 2025, toxic algae was reported at the lake, prompting Thurston County to issue a public advisory to avoid swimming there. Samples collected from the lake detected Microcystins levels above state recreation guidelines. The advisory ended on July 16 after two satisfactory samples.