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record (1939-present) is 9,170 fP/s occurred in 1945. The f1Jod of record of 39,900 ft3/s for Cherry Creek near Melvin (06712500) occurred on June Hi. 1965; the maximum paleoflood is about 74,000 ft3/s (fig. 4) in at least several thousald years. The June 16 peak of 59,000 ft3/s entering Cherry Creek Reservoir reflected the M,lvin peak at 1830 hrs and runoff from the ungaged area (27 mi2) between the Melvin gage and the Reservoir, primarily Piney Creek (14,100 ft3/s) at 1500 hrs (Matthai, 1969). 3. The largest flood for Cherry Creek near Franktown (06712500) resulted from the failure of Castlewood Canyon Dam during a rainstorm on August 3, 1933 (Matthai, 1969). A rainstorm produced 3 to 9 inches of rain in about 9 hours in upp"r Cherry Creek basin (U.S. Army Corps of Engineers, 1976). Good to excellent paleoflood evdence (top of coarse bouldery flood-deposited sediments) for the 1933 flood is preserved at many sites in upper Cherry Creek basin (e.g., figs. 2 and 3). The maximum paleoflood upstream from Castlewood Dam is about 30,000 ft3/s. The maximum paleoflood downstream from Castlewood Dam is about 44,000 ft3/s (rainstorm flood exacerbated by the dam-failure flood) at the gage (06712000) near Franktown. Because Cherry Creek is constrained by bedrock on the bed and walls, the 1933 paleoflood deposits represent the largest flood in more than 10,000 years at the Franktown gage and upstream from Castlewood Canyon Dam. 4. No streamflow-gaging stations have been operated on Box Elder Creek. Historical reports indicate upper Box Elder Creek (Running Creek) has not had significant flooding since at least the early 1880s (Follansbee and Sawyer. 1948; Matthai. 1969; Water Resources Consultants. 1979; CH2MHILL, 1995). A flood of 4,700 ft3/s for Box Elder Creek downstream from 1-70 near Wiggins on May 30, 1948 was estimated by the U.S. Geological Survey using the slope- area method (McKee and Doesken, 1997). The flood of record is about 6,000 ft3/s in lower Box Elder Creek in May 1969, which was estimated from records since the early 1900s at Bootleg Reservoir (fig. 1) in Adams County (CH2MHILL, 1995). The largest flood in Running Creek at Elizabeth (upper Box Elder Creek) occurred in May 1935; flood damages were limited to a small wooden bridge that washed out, and erosion of part of the railroad embankmentlceated low in the floodplain (Water Resources Consultants, 1979). The maximum paleoflood near Elizabeth is about 9,000 ft3/s in at least several hundred years to several thousand years. The maximum paleoflood in Adams County just downstream from 1- 70 is about 8,700 ft3/s during the past 100 to 500 years. There may be slightly higher and substantially PSis corresponding to a paleoflood. Additional fieldwork is needed to better define this larger paleoflood. The maximum paleoflood is about 4,700 ft3/s for Coyote Run near its confluence with Box Elder Creek just north of 1-70. The headwaters of Running Creek (upper Box Elder Creek basin) have substantial exposed bedrock and shallow soils, which exacerbate runoff potential. However, Running Creek near County Road 86 (drainage area about 5.5 mi2) has a maximum paleoflood of about 1,600 ft3/s in at least several hundreds of years (based on a thick soil-profil" development). Maximum paleofloods near the headwaters are relatively small (table 1), which can be used to infer that maximum rainfall amounts are smaller than in nearby basins closer to the crest of the Palmer Divide. Deep well-drained soils in downstream contributing areas to Running and Box Elder Creeks (Water Resources Consultants, 1979; CH2MHILL, 1995) and thick sand-bed channels (high infiltration) also contribute to relatively small peak flows. The average width of 8 fl I I I I I I I I I I I I I I I0I I I