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The upstream limit of the alluvium as mapped (based on flood plain and channel meander features) terminates at approximately the confluence of the North Fork and Middle Fork of Bolton Draw. There is not a precise upstream contact between the alluvium and the surrounding uphill terrain in this vicinity, but 'rather the contact is very gradational. However, from this point (approximately 300 feet upstream from weir #1), the North Fork of Bolton Draw has not recognizable channel for a distance of at least 300 feet." This area is shown on Figure 3. Quoting again from Page 109: "The channel picks up again at this point and continues up to the vicinity of the M&T access road..." This area has also been mapped on Figure 3 as an active stream channel according to OSM definition. This region does not however, contain an alluvial soil as indicated by the Ryan Park Soil (Unit 1) also shown on Figure 3. Although this region contains an active stream channel, it does not contain any active or inactive flood plains, terraces, abandoned oxbows or other geomorphic characteristics indicative of alluvial valley floors. Furthermore, this stretch of channel contains no evidence indicative of subirrigation as may be found in the downstream regions mapped as Qal on Main Bolton Draw. Continuing the quote from Page 109: "The channel continues upstream past the M&T access road continually narrowing until it again disappears about 500 feet before it reaches the southern boundary of the lease area (C-30168)." This region of the active stream channel has also been mapped on Figure 3, showing the area where no recognizable channel exists. It is within this region that the alluvial soil unit exists (Unit 8 as shown on Figure 3). Quoting from Page 109: "Partially within Pit 2 and extending downstream to about the M&T access road, there is mapped a second unit of alluvium which is isolated from the unit further downstream. This area has been mapped as an unnamed alluvium (Unit 8 on the soil map, Appendix E). This soil which is composed of thick quantities of silt, has a large water holding capacity and does contain some groundwater. This minor pocket of perched alluvial groundwater is, however, isolated from the main water table aquifer occuring downstream in the vicinity of Well 2." (See Figure 3). "Surface water readily infiltrates this silt until it reaches an impermeable underclay. Hence, small quantities of perched groundwater are stored in this vicinity." This phenomenon is the reason why portions of soil unit 8 have subirrigated plant species. -7-