That river in the picture is the Missouri, below the Fort Peck Dam. Old-timers who were here before the dam was built, talked about the June Rise as when the mountain runoff would get here. The June Rise can be delayed a bit or even non existent these days. Depends on how full the dam might be and how much snow melt is headed this way. Right now, the river is coming up a bit because the Corps is starting to let a bit more out of the dam to be ready for this year's influx of water. Dam is currently above full pool and into the flood control stage. The Corps doesn't think it will get quite as full as it did last year but they're bumping releases to around 20,000 CFS. For the guys downstream, the current outflows from the Yellowstone are around 80,000 CFS which combined with the Missouri will push inflows to Garrison up to 100,000 CFS. Drove across the Yellowstone last weekend and it is high and muddy with mountain runoff.