Alvaro Saborio got RSL's first goal in the 14th minute, Findley made it 2-0 in the 79th minute and Gonzalez notched his first goal of the season in stoppage time to cap the one-sided victory.
Salt Lake (10-4-4) has lost once in 13 games.
United (3-12-3) got its best chance at the 30-minute mark when Branko Boskovic chipped the ball over the head of goalkeeper Nick Rimando but it sailed narrowly over the crossbar.
2014: The Year in Fashion [PHOTOS]
UPI Sports Results for September 19, 2014