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Through the work done on the pilot study, a methodology was developed to standardize data identification, collection, transfer and conversion into digital format. Current data is defined here as "data generated post June 1990 GCES/GIS base map." This methodology, along with a quality check of each iteration within the methodology, is now being applied in the development of the current data sets for both monitoring and specialized study sites. Verification and Transfer River trips were made during the summers of 1990, 1991, and 1992 to map features in accordance with the classification scheme. The mapping effort was segregated into three trips because of the limited temporal window available during the scientific flows. Bias of the 1991 data, caused by physical. changes that might have occurred within the monitoring sites between trips, was eliminated by mapping only classes represented on the photographic base map product. The field work for monitoring sites No. 1 through 5 was completed in 1990; monitoring sites No. 6 through 11 were mapped in 1991; sites No. 12 and 13 were completed in 1992. Emphasis was placed on mapping the new and old high water vegetation, but the mapping effort also included other features highlighted in the classification scheme. To standardize the study area being mapped, field work for sites No. 1 through 11 was done during the scientific low flow (5,000 ft3/s) represented by the CIR photography and base map products. Field mapping for sites No. 12 and 13 was done at a steady flow of 8,000 ft3/s. The 1990 CIR photographs blown up from 1:4,800 to 1:2,400 scale with registered mylar overlays were carried into the field and defined classes were mapped on the overlays using a mylar pencil (fig. 9). Classes were delineated on each photo within the monitoring site from the top of the old high water zone down to the Colorado River. The interpreted mylars were then quality checked in the field by a second party for inconsistencies and classifications in the mapping. A light table was used to check for any missing data not identifiable in the field. The mylar overlays were used as templates to classify and map information from the 1:2,400 orthophoto base map product. After templating was completed, the transfer from CIR, photo to georeferencd base map begins. A mylar overlay is affixed to the orthophoto grid and is registered by drafting the 200-meter Arizona State Plane grid tics represented on the orthophoto with a 0.012-inch-width drafting pen. The orthophoto grid is placed over the classification template and all identified classes are drafted to the registered overlay as they are depicted on the orthophoto (fig. 10). By the definition of an orthophoto, this step georeferences and rectifies the spatial data. An orthophoto is a photograph showing images of objects in their true orthographic positions. Orthophotos are therefore geometrically equivalent to conventional line and symbol planimetric maps which also show true orthographic positions of objects. Because they are 15