Question

what influenced the armed standoff between two rival native american tribes in Wounded Knee, South Dakota

Answer 1

The greatest influence was the Ghost Dance. A Spiritual Dance that was thought to make the dancer immune to bullets. The Native Americans believed that they had been defeated and forced onto the reservations due to angering the gods and had abandoned their traditions and ways. 
The other influence was the gold on the lands where the tribes had been placed. The land, originally thought to be worthless, was found to possibly contain gold making it priceless. <span />

Answer 2

Wounded Knee, dwelled on the Pine Ridge Indian Reservation in southwestern South Dakota, was the place of two battles between North American Indians and legislators of the U.S. government. An 1890 killing transmitted some 15 0Native Americans lifeless, in what was the final conflict between central troops and the Sioux.

The largest impact was the Ghost Dance. A Spiritual Dance that was believed to cause the dancer immune to bullets. The Native Americans believed that they had been defeated and taken onto the restrictions due to offending the gods and had rejected their faiths and customs.

The other part was the gold on the estates where the societies had been set. The land, previously considered to be unimportant, was determined to seemingly cover gold executing it valuable.