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;"14 - channel emerges from its entrenched course and numerous very recent mudflows have come down the deep channel and spread out over the gentler slopes north of the river. Detailed topographic maps and aerial photos show four well-defined modern distributary channels across the flood area (plate 3). The area involved in very recent mud flooding is approximately 2,000 feet in length and 500 feet in average width. Studies of aerial photographs of different ages'showmany changes of topography and vegetation caused by mud floods between 1945 and 1970, and local residents describe at least three mudflow".events. since 1965. We consider the entire area of. contemporary mud flooding on lower Slate Creek to be unsuitable for.viable. residential or commercial development unless and until a workable, economical and environmentally acceptable solution to the problem of frequent mud floods is devised and implemented. Some of the factors which we believe will affect the engineering of pos- sible control structures and the cost of their construction and mainten- ance will be discussed in a later section of this report. Figures 2, 3, 4, 5, 6, 7 and 8 depict the general appearance and condition of the Slate Creek mudflow terrain. Carbonate Creek Mudflows (2b) Carbonate Creek descends from a steep and sizeable drainage basin .(approximately 3,500 acres) on the slopes of Mt. Daly and Elk Mountain, and follows a deeply entrenched and actively eroding channel adjacent to and east of the major mudflow fan. Just north of the Marble townsite, Carbonate Creek emerges from the steep-walled canyon it has.cut into the Mancos Shale, and flows in a normal channel through the town to its con- fluence with the Crystal River. The area between the mouth of the