 Ben AffleckSheriff Bryce Hammond | Sheriff Bryce Hammond |
 Peter O'TooleDr. Timothy Flyte | Dr. Timothy Flyte |
 Rose McGowanLisa Pailey | Lisa Pailey |
 Joanna GoingJennifer Pailey, M.D. | Jennifer Pailey, M.D. |
 Liev SchreiberDeputy Stuart 'Stu' Wargle | Deputy Stuart 'Stu' Wargle |
 Nicky KattDeputy Steve Shanning | Deputy Steve Shanning |
 Clifton PowellGen. Leland Copperfield | Gen. Leland Copperfield |
 Rick OttoScientist Lockland | Scientist Lockland |
 Valerie ChowScientist Yamaguchi | Scientist Yamaguchi |
 Adam NelsonScientist Burke | Scientist Burke |
 John HammilScientist Talbot | Scientist Talbot |
 John Scott CloughScientist Shane | Scientist Shane |
 Michael DeLorenzoSoldier Velazquez | Soldier Velazquez |
| WWilliam HahnScientist Borman | Scientist Borman |
| RRobert HimberScientist Walker | Scientist Walker |
 Bo HopkinsAgent Hawthorne | Agent Hawthorne |
 Robert KnepperAgent Wilson | Agent Wilson |
| PPaul SchmidtChurch Soldier | Church Soldier |
 Dean HalloSgt. Harker | Sgt. Harker |
 Clive RosengrenCommanding Officer | Commanding Officer |
| EEdmund WysonCpl. Guthrie | Cpl. Guthrie |
 Luke EberlTunnel Boy | Tunnel Boy |
 Judith DrakeHilda | Hilda |
 Yvette NiparCowgirl | Cowgirl |
 Lonny ChapmanOld Man at Bar (uncredited) | Old Man at Bar (uncredited) |
 Linnea QuigleyWoman in Room 204 (uncredited) | Woman in Room 204 (uncredited) |
