There are 3 books in the California Zephyr series.
The California Zephyr series does not have a new book coming out soon. The latest book, The Ghost in Roomette Four (Book 3), was published in April 2018.
The first book in the California Zephyr series, Death Rides the Zephyr, was published in September 2013.
The California Zephyr series primarily falls into the Mystery genre.