Jon Jeffrey Challberg, 38, was last seen on February 6, 1986, in Sacramento, California. That evening he attempted to swim across the Sacramento River but never made it to the other side and has not been heard from since.

He was described as a white male about 5 feet 11 inches to 6 feet 0 inches tall. Beyond the attempted swim and his disappearance, few details are available and the case remains classified as a missing person.

Does anyone remember seeing Jon in Sacramento around February 6, 1986, or have information about that stretch of the river that could help investigators?