Laserfiche WebLink
Level 2 Potential Conservation Area (PCA) Report <br />Name Middle La Plata River Site Code S.USCOHP"24630 <br />IDENTIFIERS <br />Site ID 2075 Site Class PCA <br />Site Alias None <br />Network of Conservation Areas (NCA) <br />NCA Site ID NCA Site Code NCA Site Name <br />No Data <br />Site Relations Shares small portion of boundary with Red Mesa (S.USCOHP" 24930). <br />LOCATORS <br />Nation United States Latitude 371409N <br />State Colorado Longitude 1080224W <br />Quad Code Quad Name <br />37108-B1 Kline <br />37108-C1 Hesperus <br />County <br />La Plata (CO) <br />Watershed Code Watershed Name <br />14080105 Middle San Juan <br />SITE DESCRIPTION <br />Minimum Elevation 7,200.00 Feet 2,194 56 Meters <br />Maximum Elevation 8,110.00 Feet 2,471.93 Meters <br />Site Description <br />The Middle La Plata River site is located south of the Town of Hesperus. The headwaters of the La Plata <br />River are within the Cumberland Basin in the La Plata Mountains. The La Plata River flows through a <br />moderately steep canyon that follows USFS Road 571/County Road 124 and then State Highway 140. The <br />first large ditch on the La Plata River is just south of Mayday. Several other ditches are located along its <br />course including the Big Stick Ditch and Hay Gulch Ditch. Due to the intensive irrigation demand, the La Plata <br />River is an intermittent stream after Hesperus, and is completely dry by mid -summer. Several other <br />anthropogenic forces threaten the viability of the La Plata River, e.g. residential development, gravel pits and <br />improper grazing. Additionally, the southwestern portion of Colorado has experienced a severe drought over <br />the past years and this cumulative lack of precipitation has exacerbated the problem of keeping a constant <br />flow in the La Plata River The element of concern, Populus angustifolia/Betula occidentalis plant community, <br />is indicative of high groundwater levels or presence of springs. The fact that this plant community is still <br />present, albeit degraded, does indicate a high groundwater table. Cottonwood regeneration and saplings <br />were also observed during the field visit. The sparse (approximately 15% cover) tree canopy is dominated by <br />narrowleaf cottonwood (Populus angustifolia) with lanceleaf cottonwood (Populus acuminata). The shrub <br />layer, approximately 50% cover, consists of river birch (Betula occidentalis), alder (Alnus incana), river <br />hawthorn (Crataegus rivularis), Rocky Mountain juniper (Juniperus scopulorum), and Russian olive <br />(Elaeagnus angustifolia). The forb layer is very sparse dominated by non -natives: mullein (Verbascum <br />thapsus), houndstongue (Cynoglossum officinale), butter and eggs (Linaria vulgaris), Dalmatian toadflax <br />(Linaria dalmatica), spotted knapweed (Acosta maculosa), and musk thistle (Carduus nutans). The graminoid <br />layer is also sparse and dominated by hay grasses e.g., timothy (Phleum pratense), Kentucky blue grass <br />(Poa pratensis), and orchard grass (Dactylis glomerate). The uplands are dominated Gambel's oak (Quercus <br />gambelh) and big sagebrush (Artemisia tridentata) with cheatgrass (Bromus tectorum) <br />Kev Environmental Factors <br />No Data <br />Climate Description <br />No Data <br />Land Use History <br />No Data <br />Cultural Features <br />No Data <br />Copyright© 2017. Colorado State University. Colorado Natural Heritage Program. All Rights Reserved <br />Print Date 7 12 2017 <br />