Colony observed while doing spring bird survey at Prairie City SVRA. Large streams of Tricoloreds passing over state vehicular recreation area. Visually followed to colony in several stands of blackberry vines on Aerojet property. Lots of activity in and out of substrate. Colony easily viewable (and best) from park entrance station. Also can be seen somewhat from White Rock Road pullout by sharp turn from Grant Line Rd to White Rock Road, but vines/water is in a depression. Contact Sarah Lose, environmental scientist, at Prairie City SVRA if contact info is needed for Aerojet. Photos taken of colony area.