A salesman and his son Tommy are driving up from California to go fishing on a river in Oregon. As they talk on the ride, Tommy says that he wants to be a salesman when he grows up. He asks his father about what he had wanted to be when he was Tommy's age, and his father said that he had wanted to discover a hidden cave with a secret in it. Tommy said he also had this dream. When they stop for dinner, the father asks the waitress if she remembers him. After a minute, she does: he had come to the restaurant many times after fishing with friends. The waitress tells them that there aren't any fish in the rivers anymore, but she heard about a lost lake that feeds the rivers and might still have big trout in it. She says that many people have tried to find it, but it is difficult. Tommy and his father want to find it. After spending the night in a motel, they wake up early and stop by the restaurant for breakfast, then head out to the river. They hike for about an hour, following the river up, but then they come across a gorge that makes it impossible to walk. They go around the gorge through dense vegetation, slowly hacking through the brush with a machete. After making it through the vegetation, they stop to rest. The father says he sees a knoll and wants to go to it to see if he can see the lake from there; he tells Tommy to wait and rest until he gets back. At the knoll, the salesman sees a timber cruiser with a notebook. The man comes over to him and tells him that he's on private property. he says that there's a no trespassing sign on the road, but realizes that the salesman wouldn't have seen it if he'd followed the creek up. The salesman asks about the lake, the timber cruiser says that it was just ahead by a fork in the land, but it disappeared years ago and now you can't tell it had ever been there. The timber cruiser offers the salesman a ride back in his truck, but the salesman declines. When the salesman returns to his son, Tommy is eager to get going. The salesman, not wanting to crush the boy's spirits, continues on, letting them explore one side of the fork, knowing that they won't have time to check the other.