USGS Water-Year Summary 2018
09471550 SAN PEDRO RIVER NEAR TOMBSTONE, AZ
LOCATION - Lat 31°45'03", long 110°12'02" referenced to North American Datum of 1927, in SE 1/4 sec.28, T.19 S., R.21 E., Cochise County, AZ, Hydrologic Unit 15050202, in Spanish land grant of San Juan de las Boquillas y Nogales, on right bank 0.5 mi downstream from Willow Wash, 2.6 mi north of Fairbank, and 8 mi northwest of Tombstone. (unsurveyed).
DRAINAGE AREA - 1,740 mi², 696 mi² of which is in Mexico.
PERIOD OF RECORD - Apr. 1967 to Sept. 1986, Oct. 1996 to current year.
GAGE - Water-stage recorder. Elevation of gage is 3,780 ft above sea level, from topographic map.
EXTREMES FOR PERIOD OF RECORD - Maximum discharge, 24,200 ft³/s Oct. 9, 1977, gage height, 11.40 ft, from rating curve extended above 4,900 ft³/s on basis of slope-area measurements at gage heights 8.89 ft and 11.40 ft; no flow at times during most summers.