Randy Brown became the first person to hike the 116-mile perimeter of the Salton Sea in June 2015. Now Brown’s hike, which he completed during 105 to 110-degree weather, and the problems the sea is facing are the subject of a documentary that is set to debut at the Oceanside Film Festival on Monday.The Salton Sea is California’s largest lake. The sea, which is located in both Imperial and Riverside counties, is shrinking and thus exposing the lakebed that turns into dust when the wind blows.