Some of these pictures and descriptions may give away plot details that you might not want to know before watching the film.
This is an adventure romance tale that takes place in the Okefenokee swamp in Georgia, where it was also filmed. A voiceover in the beginning tells us some things about the swamp including that it is the breeding ground of the deadly water moccasin. It's a re-make of a 1941 movie "Swamp Water" also shown on this site, which also stars Walter Brennan and includes an almost identical snake bite scene.
A young man named Ben (Jeffrey Hunter) goes deep into the forbidden area of the swamp to find his runaway dog. At one point as he travels we see a snake on a branch above him but he doesn't see it. Eventually he gets lost and is captured by Jim (Walter Brennan) and his daughter Laurie (Jean Peters) who are fugitives living and hiding out in the swamp. Jim tells Ben that two trappers who Ben and his father found dead were "cottonmouth bit." One night Jim goes to a spring to drink some water when a Cottonmouth resting at the spring strikes out and bites him on the face. Ben cuts the wound and Laurie sucks and spits the poison. They think he died so they prepare to bury him. When they go look for his body, they find that he got up and seems to be perfectly fine - with no logical explanation for why this happened. (Maybe it was a dry bite.) Later, when the three are paddling their boats hunting for otters, we see a snake on a branch above Ben. Laurie yells to him to be careful of the cottonmouth. He sees it close to his face, freaks out, loses control of his boat, falls in the water and hits his head knocking him out and is nearly eaten by alligators.
One of the reasons I watched this was to see more of Jean Peters who was so good in Sam Fuller's noir classic Pickup on South Street and in Niagara (made by the same director as this one.) She made only a few films before her husband Howard Hughes lured her away from the business. She's a bow-hunting wild woman in this one, but she does get a chance to clean up put on a nice dress in one scene.
Both snakes we see on branches overhead are Boa Constrictors, snakes not found anywhere near the Okefenokee swamp, but the Cottonmouth appears to be just that. When it strikes you can see that it never reaches Walter Brennan's face. A Spokane newspaper article from 1952 describes that the snake was a real cottonmouth that was encouraged to strike after it was tickled on the head with a feather. The snake and Brennan were filmed two weeks apart then the two films were merged to make it look like they were together.
Gloria Cesar is described as a beautiful Peruvian woman who was the movie's "snake director,"and the only female snake director in Hollywood, who has rented her snakes to many pictures. She explains that most snakes we see in movies are dead. She injects her snakes with 50 shots of formaldehyde then molds their body into the postion needed for a scene, soaking them in formaldehyde to keep them supple untile needed.