From the Chaosium website:
Three Wild West Call of Cthulhu Adventures set in the New Mexico Territories
The year is 1851.
‘Night of the Boot Hill Bandits’: This Call of Cthulhu adventure is suitable for a single gaming session with beginning players. It's set in a tiny own, Elota, New Mexico, in the year 1851. It attempts to strike an even balance between combat and investigation.
‘The Night of the Kachina’: This Call of Cthulhu adventure is suitable for a single gaming sessions with any experience level players. It's intended for an event or convention but can easily be integrated into a continuing campaign. This adventure is weighted more toward combat than investigation but does require the players do some basic investigation. As I described it to a friend: "It's got family values, political suck-ups, cocktail parties, possessed dolls, disadvantaged orphans, fire vampires, a sword fight with an evil Spaniard, a cliff jump on horseback, evil Indian Shamans, and it starts with a sanity check! YEE HAW!"
‘The Night of the White Buffalo’: This adventure is set in the New Mexico territory of the United States late in the year 1851. It is a continuation of the adventure ‘The Night of the Kachina’ but can be played separately. In ‘The Night of the Kachina’, the investigators became involved in a plot to disrupt the new United States government. Let's see what happens next!