In Oregon, canine actor “Benji” has gone missing while filming a movie on location. Benji’s trainer, Frank Inn, tells a television reporter that he and Benji had been on an open fishing boat in the Pacific Ocean when a storm came in, capsizing the vessel. Inn fears Benji is dead, but the movie producers plan to search the wilderness coastline with a helicopter. The next day, Benji lies in the brush near the shoreline when a helicopter flies overhead, but he goes unnoticed. Benji wanders through the woods and comes across a female mountain lion perched atop a boulder. Just then, a hunter shoots the lioness. Benji licks her wound, and tugs at her ears, but the animal is dead. A few minutes later, the hunter comes and carries his prey away. When the helicopter flies overhead again, Benji runs after it, barking to no avail. Benji hears noises and discovers the dead lioness’ four baby mountain lions, just a few weeks old. One of the cubs runs toward Benji, but the dog picks him up in his mouth and returns him to the lion den amidst the rocks. When the cub tries to climb out again, Benji barks to keep him in the den. Benji makes friends with the cubs, then gets berries for them, but they refuse the food. While hunting, Benji comes face to face with a rabbit, but licks it twice, and leaves. Benji finds a cabin where a quail is being cooked over an open fire. When the hunter takes the cooked bird inside, Benji spies two additional dead quails hanging on a line nearby. He grabs one of the birds and drags its body back to the den for the cubs. The next day, a young deer runs by and two otters play in a nearby creek while Benji collects rocks to make the den higher so the cubs cannot get out. Benji returns to the cabin to get the other dead quail, but the hunter catches him and ties him up. Reading Benji’s collar, the hunter remembers there is a reward for the dog’s rescue. When the hunter goes inside, Benji tugs at the rope, trying to break free. Just then, a black wolf growls at Benji. When the hunter comes outside, the wolf runs away. As Benji paces the area as far as the rope will allow, the wolf comes back and Benji makes a commotion. The hunter comes outside to see about the noise, scaring the wolf away. The hunter briefly unties Benji while trying to unravel his rope. Benji grabs the other dead quail in his mouth and runs back to the cubs. Benji sees an adult female mountain lion and barks, but she growls at him. Benji then moves the cubs to a new location, carrying each of them individually in his mouth. While doing this, the helicopter flies overhead and Benji sees his trainer in the window. By the time Benji has finished moving the cubs to the new den, another animal has eaten the quail. Benji searches for more food, barking at the cubs when they try to follow him. Meanwhile, the wolf begins to movie in on the cubs, but the helicopter flies overhead, scaring him away.
The next day, Benji sees the mountain lion and the wolf nearby. The wolf chases Benji, but the dog manages to elude him. Later, the four cubs follow Benji along the path. A large brown Kodiak bear comes into the clearing. Benji and the cubs hide, but one of the cubs runs toward the bear, hissing at him. The bear growls, scaring the cub back to the hiding place. When the bear moves toward them, Benji barks and runs the opposite direction. The bear gives chase, but soon loses interest. However, the wolf appears again and chases Benji. They run a long distance over the mountain until Benji leads the wolf to the bear. The bear growls and scares the wolf away. Later, the mountain lion drinks from the stream when one of the cubs approaches. Just then, the helicopter flies overhead, scaring the lioness away. When Benji spots the lioness again, he barks at the cubs to follow him across the stream. The helicopter lands nearby and Frank Inn gets out, calling for Benji. The dog looks between his master and the cubs playing, but does not make a move. Unaware Benji is nearby, Inn gets back into the helicopter and flies away. Later, an eagle swoops down, grabs one of the cubs in its talons and flies off. When the eagle later flies near the three remaining cubs, Benji barks to scare it away in time. Benji spots the lioness and sees the cub that the eagle took following closely behind her. Benji barks at her repeatedly until she gives chase, but Benji loses her along the way. Although Benji almost falls into the deep ravine, he climbs to safety. From the top of the cliff, Benji sees the cubs below. Benji finds the lioness near the waterfall. Benji runs to get the cubs, but finds the wolf watching the cubs. Benji barks at the wolf, then bites at him. The cubs hide under a rock where the wolf cannot reach them. Benji jumps on the wolf’s back, then runs away. As the wolf gives chase, Benji runs up the side of the mountain and leads him to the edge of the cliff. The wolf runs off the cliff. Benji lures the cubs to come out from under the rock and carries one of the cubs up the side of the steep mountain in his mouth. At the top, Benji leaves the first cub, then goes back down the cliff to get the others. With all three cubs on the mountaintop, the mountain lion appears. She sniffs the cubs and nuzzles them. The cub that has been following the lioness comes into the meadow, sees its siblings and runs to join them. The lioness lies down and the four cubs nurse from their adoptive mother. Benji goes to rest in plain sight in the meadow just as the helicopter approaches.