On screen
Cast
31 credited performers
Tim Holt
Lt. Cmdr. John 'Twill' Twillinger
Audrey Dalton
Gail MacKenzie
Hans Conried
Dr. Jess Rogers
Barbara Darrow
Jody Simms
Max Showalter
Dr. Tad Johns
Artwork unavailable
Harlan Warde
Lt. Robert 'Clem' Clemens
Gordon Jones
Sheriff Josh Peters
Mimi Gibson
Sandy MacKenzie
Marjorie Stapp
Connie Blake
Jody McCrea
Seaman Fred Johnson
Wallace Earl
Sally
Artwork unavailable
Dennis McCarthy
George Blake (lab assistant)
Sarah Selby
Mrs. Simms
Milton Parsons
Lewis Clark Dobbs
Charles Tannen
Seaman Wyatt (Radioman)
Artwork unavailable
Robert Benevides
Seaman Morty Beatty
Artwork unavailable
John Carlyle
Monster Victim
Artwork unavailable
John Close
Deputy Larry
William Forrest
Admiral Greenhouse
Artwork unavailable
Gil Frye
Deputy Scotty
Joseph Hamilton
Other Lock Watchman
Charles Herbert
Boy with Morty's Cap
Byron Kane
Coroner Nate Brown
Artwork unavailable
Ralph Littlefield
Gatekeeper
David McMahon
Patterson
Ralph Moody
Watchman at Lock 57
William Swan
Seaman Howard Sanders
Artwork unavailable
Hal Taggart
Davis - Resort Owner
Mack Williams
Captain Masters
Artwork unavailable
Dan Gachman
Deputy Brewer
Artwork unavailable
Michael Dugan
Clarke