Epsom Salts Monorail crossing Searless Lake Photograph of the monorail through the Slate Range, California, 1921-1925. Caption: ABOUT 1921 OR 1922 THIS MONORAIL WAS BUILT ACROSS SEARLES LAKE AT WESTEND INTO THE SLATE RANGE TO A DEPOSIT OF MAGNESIUM SULFATE. IT WAS NEVER SUCCESSFUL AND WAS LATER ABANDONED.