The lake has many singular traits. Three hours northeast of San Francisco, it is 22 miles long and 12 miles wide, and it is divided roughly in half by the state line that separates California and Nevada. Tahoe sits at the entrance to the Sierra Nevada, with a surface elevation of 6,200 feet. It is drained by only one river, the Truckee, and it is almost 100 percent pure, like bottled water. It has only one keelboat marina, one island and one true bay, named Emerald. However, the bay is so stunningly beautiful that there is probably no need for any others.