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DI8 FLOODS OF 1965 IN THE UNITED STATES from Smith Canyon, which had a peak discharge of 84,000 cfs at a site 4.5 miles upstream from its mouth, The second peak, 62,500 cfs, was from the flood crest moving down the Purgatoire River, but there had been con- siderable attenuation from the peak discharge of 105,000 cfs at the Higbee station, Had the flood crest from Smith Canyon been coincidental with the crest moving down the river, the flood at Las Animas would have been much more devastating, ARKANSAS RIVER-JOHN MARTIN DAM, COLORADO, TO GREAT BEND, KANSAS The gates in John Martin Dam were closed at 0730 hours on June 17, and nearly the entire volume of flood runoff was contained in the reservoir. However, another flood was generated on the Arkansas River in the reach between the mouth of Caddoa Creek and Lamar, Colo., from the tributaries on the south side of the river. The sum of the peak discharges on Caddoa, Mud, and Dry Creeks was almost 120,000 cfs during the early hours of June 18. Channel storage and differences in timing reduced these combined peak inflows to a peak discharge of 73,800 cfs at Lamar at 0800 hours on June 18 (fig, 9). Even with this reduction, the gaging station was inundated and ex- tensive flooding occurred in the north half of Lamar. Willow Creek, a tributary entering Lamar from the south, spread havoc in the southern and eastern parts of town. High runoff from Clay Creek, a south-bank tributary east of Lamar, added to the floodflows on the Arkansas River. The peak discharge on Clay Creek upstream from Clay Creek Reservoir was 158,000 cfs on June 18. Clay Creek Reservoir filled to capacity from inflow due to rains on June 17, and the dam failed because of the high inflow on June 18. Between Clay Creek Reservoir and the Arkansas River, highway bridges and railroads were extensively damaged (fig. 10). Big Sandy Creek enters the Arkansas River from the north between Lamar and Granada, Colo. It heads near Calhan in the area northeast of Colorado Springs, flows northeast toward Limon, and then turns southeast to the Arkansas River. The peak discharge near Calhan (60,700 cfs at 1700 hr on June 17) was caused by the storms of June 17 near Colorado Springs. The peak flow was reduced significantly by Ramah Reservoir, 9 miles downstream, and little of this flow reached the Arkansas River. Supplemental information along Big Sandy Creek was obtained by H. F. Matthai on July 13, 1965 (written commun.). Peak discharges estimated at 2,500 to 3,000 cfs occurred at Matheson, Limon, and Hugo, and one of about 8,000 cfs occurred at Kit Carson. The peak discharge near the mouth of only 3,600 cfs occurred at 0900 hours on June 17 and resulted from local rains. Other north-bank tributaries between Lamar and the State line also had only minor flood peaks except for Wild Horse Creek, which had a peak flow of 10,600 cfs at Holly on June 17.