UPDATE II: Not only did they publish a book, but they also filmed a documentary in color, called We Made the “Impossible” Tour, that was part of a lecture tour. In addition, their adventure was serialized in the Saturday Evening Post in 1957:
January 12, 1957, We Made the “Impossible” Tour, Part One: How We Motored Through the Jungle
January 19, 1957, We Made the “Impossible” Tour: Part Two: How We Went to Sea in a Jeep
January 26, 1957, We Made the “Impossible” Tour, Part Three: Island-Hopping the Spanish Main
February 2, 1957, We Made the “Impossible” Tour: Part Four: Trigger-Happy Territory
February 9, 1957, We Made the “Impossible” Tour: Conclusion:The Land of Fire – three agonizing miles of travel in southern Argentina.
UPDATE: This same book is published under a different name with some different photos: “La Tortuga an amphibious journey from Alaska to Tierra del Fuego”. I could not find a copy for sale when I last looked.
“20,000 Miles South: A Pan-American Adventure in a Seagoing Jeep from the Arctic Circle” by Helen and Frank Schreider is a great read. In the book they relate their first failed attempt to travel south in a Willys Wagon, which leads to their decision to try it in a SEEP (named La Tortuga). In 1954, they started their journey south, sharing in the book their struggles, successes and failure. At one point they try to drive down a railroad track, but are forced to give up the effort due to the damage the track inflicted on the SEEP. At another point they enter the country of Colombia by water, only to be told when they attempt to exit the country that they didn’t get the proper stamp (because they entered via the water). These are just some of the challenges they face.
I’d have to say this is one of my favorite jeep related books that I have read. After the “20,000 Miles” book they wrote the “Drums of Tonkin“, which is about a trip through Indonesia, and “Exploring the Amazon.” They also joined National Geographic as photographers and authors.
Frank died in 1974 at the age of 70. He suffered a heart attack in the cabin of his sail boat, Sassafras, while anchored off the island of Crete. I suspect that’s the way he would have wanted it. Helen was still alive and living in New Mexico at last report.
La Tortuga was re-discovered in California in 2006 and shipped to Norway. La Tortuga appears to still be for sale.
It appears you can borrow a copy of the book through the open library project. Learn more here. Here are some photos. This is a shot of the inside cover which shows the path they drove/boated:
This photo was taken after the maiden voyage in Balboa Bay, California. Helen is holding onto their dog, Dinah, who could often be found riding on top of the cabin.