It's an open secret that Tabor Evans, in this instance, is James Reasoner. And if you ask me, James is having way too much fun writing these Longarm novels. My theory is that James wants to have written for every western series there is, or ever was. Since some of the series are defunct, he's sneaking them into the Longarm novels. This time it's the gang from Easy Company.
Longarm is sent to the titular (no pun intended) Valley of Skulls to help out with some trouble there. Easy Company is having some problems of its own with Indians in the area and with a wagon train of pilgrims headed for the valley. The two stories are told in alternating chapters until they mesh toward the end of the book. Before that happens, though, James has brought in another series western character, but I'll let you find out about that one for yourself. It gave me a grin or two, though. And the plot turns out to be tied to still another series that James had a hand in.
As usual in a book by James, you get full value. Hooded stage robbers, an Indian attack on a town, fistfights, gunplay, ambushes, and sex. And all that's just in the first 75 pages or so. You can't go wrong here. Check it out.