The lowest area within the flat is the salt flat just east of Bonnie Claire at an elevation of 3943 feet. Bonnie Peak at the north end of a spur of the Grapevine Mountains and less than one mile west-southwest of the low point has an elevation of 4969 feet. Further south Grapevine Peak rises to an elevation of 8737 feet along the crest of the Grapevines adjacent to the California border. Grapevine Peak lies about six miles west of the Sarcobatus floor in the southern portion.