This vantage point is located the Tule Lake National Wildlife Refuge visitor center near Tulelake, California.  The Sheepy Ridge Trail goes up to a CCC-built lookout with grand views of Tule Lake and the Klamath Basin.  A view south reveals Lava Beds & the Medicine Lake Caldera.

Tule Lake is one of 20 listed lakes on Wikipedia classified as an ancient lake.  The lake is considered ancient if it is 1,000,000 years old or older.  It is ranked as #9 b/w 3-15 million years of age.