Christopher Martin King was 24 when he was last seen on August 2, 1974, near the intersection of Route 10 and Route 395 in the Rialto–San Bernardino area of California. He had been traveling toward Mexico and was last confirmed at the Tijuana border crossing. After that sighting he vanished without a trace.

King was reportedly bound for La Paz, Baja California, having boarded a bus in Tijuana, and his plans included traveling through Guadalajara, Mexico City, Merida and Isla Mujeres, with a possible final stop in the Yucatan Peninsula. He carried a red nylon backpack with a full set of camping gear, wore sport shirts, jeans or cut-offs and Wallabee desert boots, and had sandy blond hair, blue eyes, glasses with wide metal frames and a birthmark on his abdomen.

Decades of inquiries have produced no conclusive leads. DNA and fingerprint submissions have been made in attempts to locate him, but there is no confirmed information about what happened after he crossed into Mexico. If anyone knew Christopher, traveled the same routes in 1974, or has information about his movements after Tijuana, please share what is known.