Soap Lake is a mineral-rich lake located near Soap Lake, Washington. The lake's unique mineral composition and therapeutic properties have attracted visitors for centuries, with evidence of human use dating back over 10,000 years. The lake's hydrology is fed by underground aquifers, and its specific surface flow comes from the groundwater seeping through the lake's porous basalt bedrock. Snowpack from the surrounding mountains also contributes to the lake's water supply. Agricultural and recreational uses of the lake include fishing, boating, and birdwatching, as well as irrigation for local farms. The lake is also known for its healing properties and has been used for medicinal purposes for decades, with local resorts offering spa treatments and therapeutic soaks.