Build a movie plot around this: Where is the climactic gun battle? "Agua Verde"
A:
In Texas in 1913, Pike Bishop (William Holden), the leader of a gang of aging outlaws, is seeking retirement with one final score: the robbery of a railroad office containing a cache of silver. They are ambushed by Pike's former partner, Deke Thornton (Robert Ryan), who is leading a posse of bounty hunters hired and deputized by the railroad. A bloody shootout kills several of the gang. Pike uses a serendipitous temperance union parade to shield their getaway, and many citizens are killed in the crossfire.Pike rides off with Dutch Engstrom (Ernest Borgnine), brothers Lyle (Warren Oates) and Tector Gorch (Ben Johnson) and Angel (Jaime Sanchez), the only survivors. They are dismayed when the loot from the robbery turns out to be a decoy: steel washers instead of silver coin. The men reunite with old-timer Freddie Sykes (Edmond O'Brien) and head for Mexico.Pike's men cross the Rio Grande and take refuge that night in the village where Angel was born. The townsfolk are ruled by Gen. Mapache (Emilio Fernandez), a corrupt, brutal general in the Mexican Federal Army, who has been ravaging the area's villages to feed his troops, who have been fightingand losing tothe forces of revolutionary Pancho Villa. Pike's gang makes contact with the general. A jealous Angel spots Teresa, his former lover, in Mapache's arms and shoots her dead, angering Mapache. Pike defuses the situation and offers to work for Mapache. Their task is to steal a weapons shipment from a U.S. Army train so that Mapache can resupply his troops and appease Col. Mohr (Fernando Wagner), his German military adviser, who wishes to obtain samples of America's armaments. The reward will be a cache of gold coins.Angel gives up his share of the gold to Pike in return for sending one crate of the stolen rifles and ammunition to a band of rebels opposed to Mapache. The holdup goes largely as planned until Deke's posse turns up on the very train the gang has robbed. The posse chases them to the Mexican border, only to be foiled again as the robbers...