USGS Water-Year Summary 2019
14240446 CASTLE LAKE NEAR MOUNT ST. HELENS, WA
LOCATION - Lat 46°15'23", long 122°16'28" referenced to North American Datum of 1983, in SE 1/4 SW 1/4 sec.14, T.9 N., R.4 E., Cowlitz County, WA, Hydrologic Unit 17080005, Mount St. Helens National Volcanic Monument, on right bank near outflow of Castle Lake, 5.0 mi north by northwest of the northwest edifice of Mount St. Helens (at Toutle Glacier).
DRAINAGE AREA - 3.10 mi².
- WDR WA-04-1: 2003. Drainage area revised in 2017.
PERIOD OF RECORD - October 1993 to current year (records of contents for water year 1994 published in WDR-WA-94-1 are unreliable and should not be used).
GAGE - Water-stage recorder. Datum of gage is 2,498.95 ft above National Geodetic Vertical Datum of 1929 (U.S. Army Corps of Engineers benchmarks); gage readings have been reduced to elevations above National Geodetic Vertical Datum of 1929. To convert to North American Vertical Datum of 1988, add 1.84 ft (USGS Level 1 GNSS survey as per USGS T&M 11-D1).
EXTREMES FOR PERIOD OF RECORD - Maximum elevation, 2,582.76 ft, Feb. 8, 1996; minimum elevation, 2,577.45 ft, Sept. 17, 2017.