Directly from the rules:
The board shows the western town Dodge City. The players fight for the dominance over the important buildings of Dodge City.
The players have stake and cards for this fight. They can purchase wooden pieces of a certain color in form of a Lady, Gunman, Sheriff, Bandit or Cowboy, which each player will place on the fields of the buildings. The Lady piece is the most expensive piece, the Cowboy the cheapest.
Events and duels keep the fight open and fair for all players. A player able to connect all important fields of a building with his pieces will win the dominance over this building and gets points for that. The Lady pieces are worth the most points while the Cowboy pieces are worth the least points.
A player having 6 points wins the dominance over Dodge City and thus the game.