There is a wealth of historical western adventures in film, radio, and television from which to draw inspiration. It is a poor GM who cannot cobble these readily available sources into encounter opportunities for your eager players.
You would be crazy to pass up Eric Hotz's "Published Wild West Wargames" page if you are a Western RPG Gamer thirsting for inspiration.
Here is a short list of additional sources if you are scrambling for ideas;
The Good, The Bad, and The Ugly stands out in every way as a classic western adventure story, let alone true grit for your historical western campaign.
I've never read any Louis L'amour, but I bet my last silver dollar there is plots to be had.
The radio adventures of The Lone Ranger and the TV series Bonanza, and Gunsmoke can provide countless story hooks.
You will also notice I do not have any issue with utilizing an adventure for more than one location on my Genre Tree.
I have no problem using the Cthulhu published adventure "The Spawn" as one of the Western, Horror adventure choices, as well as in this "Historical" branch of the Western genre tree. I even intend to use this same adventure as an option for the Espionage, Hard Boiled branch of the Genre Tree. This all will have the net effect of reducing prep time while trying to present this large grouping of genres and adventures to the players.
Western, Historical; | |||||||
1.3.1 | Cthulhu Mythos | 1.3.2.1 | Bank Robbers | 1.3.3.1 | Civil War | ||
1.3.2.2 | Cattle Rustlers | 1.3.3.2 | French & Indian War | ||||
1.3.2.3 | Mysterious Stranger |