Devil's Gulch does double-duty as both a setting book and a genre sourcebook, and given a page count of only 92 pages, that's a tall order.
It delivers both, sufficient to kick off a short Western campaign set in Devil's Gulch for a while.
On the genre sourcebook end, it provides an all important one-page listing of various aspects of the 'Code of the West' in the Old West -- measure a man by what he is today, not by his past; never try on another man's hat; give your enemy a fighting chance, etc. It's great at evoking a real sense of the times and climes of that almost mythic era.
It also gives various character professions that add on to the other more normal (time-period appropriate) professions for the era -- with a particular 'weird west' bent to them. I particularly like the snake oil hustler and the hexmaster, though the medicine man is also a welcome inclusion as well.
As a setting sourcebook, it gives a respectable number of locations in Devil's Gulch that are easily extractable to your own setting if you wish. Each location has a map, a statted-out NPC or two if appropriate, and a short but detailed description of what if found within, along with telling details that reinforce the western feel of the setting. I enjoyed little things like the lists of supplies that can be found in the general store, and how easy fires can be started in the dry, almost-entirely-made-from-wood buildings of Devil's Gulch.
The NPCs are also memorable, worthy of stealing from when looking for a random NPC walking the streets to liven up the session.
That interior art is consistent and distinctive. It's not really a photorealistic approach, but a moody, evocative, slightly cartoony feel -- kind of like the art in the Weird Western comic book The Sixth Gun and the art in Alan Moore's League of Extra-Ordinary Gentlemen -- that captures and evokes the weird western feel quite well.
If you're looking for something to expand your Weird West collection of materials, or have been hankering to run a Weird West campaign using the BRP system, this would be a fine addition to your sourcebooks.
(from my review at armchairgamer.blogspot.com)