The state's most important rivers are the Missouri, rising in southwest Montana and flowing north and then east across the state, and the Yellowstone, which crosses southeastern Montana to join the Missouri in North Dakota near the Montana border.
Distribution in South Africa. Hoverflies can be found all over the country between the sea-shores and the mountains. In total, there are at least 180 species recorded from South Africa. The number of species declines from the northeast to the southwest. However, some species have only or predominately been found in the Western Cape.
Cluster flies are capable of crawling through small openings in the walls of a structure. They hibernate in secluded parts of houses like attics and wall voids. On sunny winter days, the wall voids become warm and the cluster flies try to move toward light. Very often they find themselves in the inhabited parts of the house and the move to the windows. They cluster around the windows and they leave stains on walls and curtains if crushed. The cluster fly life cycle begins when a female lays her eggs in the soil in late summer or early fall.