Important Legacy real-time page

Available data

Select data types to graph from categories based on the way the data were collected.

Learn about the data collection categories

Continuous data

3 data types available - data from 2024-03-26 to 2026-08-03

Daily data

1 data types available - data from 2024-03-26 to 2026-08-03

Field measurements

1 data types available - data from 2024-03-26 to 2026-06-24

Discrete sample data

0 observed properties (data types) available

Statistical tables for select daily data types

0 data types available

Important information about this monitoring location

LOCATION.-- At St Mary's River State Park Dam, on Western Branch Saint Marys River, 1.2 miles northwest of Callaway, MD. PERIOD OF RECORD.-- March 26, 2024 to current year GAGE.-- Water stage recorder and crest stage gage. Datum of gage is 220.40 ft above North American Vertical Datum of 1988. REMARKS.-- Tipping-bucket rain gage with site number 381510076320001 is located at station.

Location details and information

Zoom out to see link to My Favorites

Use Explore USGS Water Data to discover additional data near this location

Metadata Element	Location Metadata	Metadata Code
Agency	U.S. Geological Survey	USGS
Location identification number	01661499	n/a
Location name	St Marys Lake near Callaway, MD	n/a
Site type	Lake, Reservoir, Impoundment	LK
Decimal latitude (WGS84)	38.25277777777778	n/a
Decimal longitude (WGS84)	-76.53347222222222	n/a
Latitude-longitude method	Interpolated from digital map	N
Latitude-longitude accuracy	Accurate to + or - .1 sec (Differentially-Corrected GPS).	1
District	Maryland	24
State	Maryland	24
County	St. Mary's County	037
Country	United States of America	n/a
Altitude of gage/land surface	-2.07 feet	n/a
Method altitude determined	GNSS2 - Level 2 Quality Survey Grade Global Navigation Satellite System	X
Altitude accuracy	0.13 feet	n/a
Altitude datum	North American Vertical Datum of 1988	NAVD88
Subbasin hydrologic unit	Lower Potomac	02070011
Drainage basin		n/a
Date of first construction		n/a
Drainage area	8.72 square miles	n/a
Contributing drainage area		n/a
Time zone abbreviation	EST	n/a
Site honors Daylight Saving Time	Y	n/a
National aquifer		n/a
Local aquifer		n/a
Local aquifer type		n/a
Well depth		n/a
Hole depth		n/a
Source of depth data		n/a

Monitoring location St Marys Lake near Callaway, MD - USGS-01661499