Dark City Games’ Legends of the Untamed West is a tactical RPG for the 1800s American West. The system is based on the wonderful Fantasy Trip system that originally was published in the micro games format. If you’re familiar with the Fantasy Trip, you know that it makes for just as good a miniatures system as an RPG.
The Perfect Captain Yahoo Group has a variant for their Red Actions game for the Indian Wars called Crazy Horse’s Fury.
Fred Diamond offers a free and simple set of miniatures rules for playing pony wars — US Cavalry vs Indians.
If you’ve wanted to try out some of the outstanding western games that are in print these days, but don’t hvae the figures, you could download and print these sheets of 19th century western gunfighters, animals and other assorted things.
Tim Greene has a good site for playing miniatures wargames set in the victorian American West. There is lots of information on the combatants, plus battle reports and rules reviews.