When a dispute occurs between a logging operation and a nearby Native American tribe, Dr. Robert Verne and his wife, Maggie, are sent in to mediate. Chief John Hawks insists the loggers are poisoning the water supply, and, though company man Isley denies it, the Vernes can't ignore the strangely mutated wildlife roaming the woods. Robert captures a bear cub for testing and soon finds himself the target of an angry mutant grizzly.
| Directing | John Frankenheimer | Director |
| Writing | David Seltzer | Writer |
| Camera | Harry Stradling Jr. | Director of Photography |
| Sound | Leonard Rosenman | Original Music Composer |
| Production | Robert L. Rosen | Producer |
| Art | William Craig Smith | Production Design |
| Editing | Tom Rolf | Editor |
| Costume & Make-Up | Ray Summers | Costume Design |
| Costume & Make-Up | Ron Snyder | Makeup Artist |
| Crew | Gilbert B. Combs | Stunts |
| Crew | Buddy Joe Hooker | Stunts |
| Crew | Janet Brady | Stunts |
| Crew | Sandra Lee Gimpel | Stunts |
| Crew | Billy Hank Hooker | Stunts |
| Crew | Everett Creach | Stunts |
| Crew | Jerry Gatlin | Stunts |
| Crew | Patty Elder | Stunts |
| Crew | Jerry Maren | Stunts |
| Crew | Cliff McLaughlin | Stunts |
| Crew | Tommy Madden | Stunts |
| Crew | Don Fox Greene | Stunts |
| Crew | Ruth A. Redfern | Stunts |
| Crew | Gene McLaughlin | Stunts |
| Crew | John Roselius | Stunts |
| Crew | Sandy Robertson | Stunts |
| Crew | Denny Arnold | Stunts |
| Crew | Alex Green | Stunts |
| Crew | Michael Adams | Stunts |
| Crew | Pamela Bebermeyer | Stunts |
| Crew | Ron Burke | Stunts |
| Crew | Gary Combs | Stunts |
| Production | Lynn Stalmaster | Casting |
| Art | George Gaines | Set Decoration |
| Costume & Make-Up | Ellis Burman Jr. | Special Effects Makeup Artist |
| Costume & Make-Up | Thomas R. Burman | Special Effects Makeup Artist |
| Crew | Edouard F. Henriques | Makeup Effects |
| Costume & Make-Up | Ann Wadlington | Hairstylist |
| Costume & Make-Up | Allan A. Apone | Special Effects Makeup Artist |
| Production | Alan Levine | Unit Production Manager |
| Production | Lindsley Parsons Jr. | Production Manager |
| Directing | Robert P. Cohen | Second Assistant Director |
| Directing | L. Andrew Stone | Assistant Director |
| Directing | Paul L. Tucker | Second Assistant Director |
| Art | Sherman Labby | Production Illustrator |
| Art | Ray Mercer Jr. | Property Master |
| Art | Gene Lauritzen | Construction Coordinator |
| Art | Arthur Shippee | Assistant Property Master |
| Sound | Gene S. Cantamessa | Sound Mixer |
| Sound | Cecelia Hall | Sound Effects Editor |
| Sound | William R. Kowalchuk Jr. | Sound Effects Editor |
| Sound | John Wilkinson | Sound Re-Recording Mixer |
| Sound | Raul A. Bruce | Boom Operator |
| Crew | Ellis Burman Jr. | Prop Maker |
| Crew | Bob Dawson | Special Effects |
| Crew | Edouard F. Henriques | Prop Maker |
| Art | James Kagel | Sculptor |
| Crew | Jor Van Kline | Special Effects |
| Lighting | Clifford Hutchison | Gaffer |
| Camera | Tom D. May | Key Grip |
| Camera | Richard Craig Meinardus | First Assistant Camera |
| Lighting | Norman Lang | Electrician |
| Camera | Ken Nishino | Assistant Camera |
| Editing | George Trirogoff | Assistant Editor |
| Editing | Michael Ripps | Assistant Editor |
| Sound | Jim Henrikson | Music Editor |
| Sound | Dale Anderson | Musician |
| Sound | Israel Baker | Musician |
| Sound | Arnold Belnick | Musician |
| Sound | Harry Bluestone | Musician |
| Sound | Norman Carr | Musician |
| Sound | Ronald Cooper | Musician |
| Sound | Isabelle Daskoff | Musician |
| Directing | John Franco | Script Supervisor |
| Crew | Peter Borkent | Stunt Driver |
