Host With The Big Hat is about the extremely friendly Mexican people who go out of their way to entertain travelers and share their large and diverse country.
Unlike most of Gardner's real-life adventure books (The Land of Shorter Shadows, Hunting the Desert Whale, Hovering over Baja, The Hidden Heart of Baja, Off the Beaten Track in Baja, Mexico's Magic Square), Host With The Big Hat has very little to do with Baja.
His adventures do begin and ends in Tijuana, but he travels by station wagon to Mexicali, goes on the rail line to Puerto Peñasco and to Los Mochis then up the Copper Canyon (only it wasn't called that yet) to Chihuahua and eventually to Mexico City, Guadalajara, Mazatlan, and the ferry to La Paz. Erle flies back to Tijuana.
A large part of this book deals with the 30,000 + unearthed (or forged) historic statues from Acámbaro that shows dinosaurs and humans (together), among other things. More than one trip makes up the book's story. The Acámbaro figurine mystery is a big part of it.

As with his other adventure books, it is filled with photos and all the dignitaries are his "good friends". Baja's famous Captain Muñoz is features as well as many of the others often included in Gardner's expeditions.