U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Datums Page Page 1 of 5 Station ID: 9432796 PUBLICATION DATE: 06/16/2004 Name: ISTHMUS SLOUGH, COOS BAY OR NOAA Chart: 18587 Latitude: 43° 21.1' N ( 43.35170) USGS Quad: COOS BAY Longitude: 124° 11.5' W (-124.19200) To reach the tidal bench marks from the intersection of U.S. Highway 101 and State Highway 243 in Coos Bay, proceed south on U.S. Highway 101 to State Highway 241 (Coos River Highway), travel east on State Highway 241 for 0.8 km (0.5 mi) over the Isthmus Slough bridge, then at the immediate end of the bridge turn right and proceed south on Olive Barber Road for 2 km (1 mi) to the Coos Head Timber Company McKenna Plant, then follow the road through the entrance gate and proceed NW to the plywood plant. The bench marks are on the Coos Head Timber Company McKenna Plant property. The tide gage and staff were at the SW corner of the plywood plant. T I D A L B E N C H M A R K S PRIMARY BENCH MARK STAMPING: 2796 A 1982 DESIGNATION: 943 2796 A TIDAL MONUMENTATION: Tidal Station disk VM#: 8792 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 43° 21.2' N ( 43.35330) LONGITUDE: 124° 11.5' W (-124.19200) The primary bench mark is a disk set vertically and flush on the east face of the 2 m x 0.5 m (8 ft x 1.5 ft) north concrete footing of a 15 m x 2 m (50 ft x 8 ft) diameter propane tank elevated 2 m (5 ft) above the ground at the SW corner of the property, 31 m (103 ft) south of the south face of the plywood plant, 8 m (26 ft) east of the east edge of the shipping dock, 2 m (8 ft) west of the centerline of the road, and 1 m (2 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 2 of 5 Station ID: 9432796 PUBLICATION DATE: 06/16/2004 Name: ISTHMUS SLOUGH, COOS BAY OR NOAA Chart: 18587 Latitude: 43° 21.1' N ( 43.35170) USGS Quad: COOS BAY Longitude: 124° 11.5' W (-124.19200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2796 B 1982 DESIGNATION: 943 2796 B TIDAL MONUMENTATION: Tidal Station disk VM#: 8793 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 43° 21.2' N ( 43.35330) LONGITUDE: 124° 11.5' W (-124.19200) The bench mark is a disk set flush in the west edge of a 11 m x 3 m x 1 m (36 ft x 10 ft x 3 ft) abandoned concrete foundation at the south end of the property, 40.29 m (132.2 ft) south of the south face of the plywood plant, 32.55 m (106.8 ft) ESE of bench mark 2796 A 1982, 8 m (27 ft) SE of the centerline of the road, 6.83 m (22.4 ft) SW of the SW corner of a shed, 5.12 m (16.8 ft) NE of the SW corner of the foundation, and 1 m (3 ft) above ground level. BENCH MARK STAMPING: 2796 C 1982 DESIGNATION: 943 2796 C TIDAL MONUMENTATION: Tidal Station disk VM#: 8794 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete footing OPUS PID: LATITUDE: 43° 21.2' N ( 43.35330) LONGITUDE: 124° 11.5' W (-124.19200) The bench mark is a disk set flush in the west concrete footing of the paint booth attached to the SW end of the planer building on the east side of the property, 18.30 m (60.0 ft) west of the west face of the sorter, 8.38 m (27.5 ft) east of the centerline of the road, 5.67 m (18.6 ft) SE of the SW corner of the planer building, 3.32 m (10.9 ft) south of the south face of the planer building, and at ground level.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 3 of 5 Station ID: 9432796 PUBLICATION DATE: 06/16/2004 Name: ISTHMUS SLOUGH, COOS BAY OR NOAA Chart: 18587 Latitude: 43° 21.1' N ( 43.35170) USGS Quad: COOS BAY Longitude: 124° 11.5' W (-124.19200) T I D A L B E N C H M A R K S BENCH MARK STAMPING: 2796 D 1982 DESIGNATION: 943 2796 D TIDAL MONUMENTATION: Tidal Station disk VM#: 8795 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete foundation OPUS PID: LATITUDE: 43° 21.2' N ( 43.35330) LONGITUDE: 124° 11.5' W (-124.19200) The bench mark is a disk set flush in the top of a concrete foundation at the east end of the resaw building, at the center of the property, east of the conveyor belts, 11.70 m (38.4 ft) NW of the SW corner of a fire wall, 10 m (33 ft) SW of the SE corner of an elevated chip bin, 5.88 m (19.3 ft) north of the south end of the concrete foundation, and 1 m (2 ft) above ground level. BENCH MARK STAMPING: 2796 E 1982 DESIGNATION: 943 2796 E TIDAL MONUMENTATION: Tidal Station disk VM#: 8796 AGENCY: National Ocean Survey (NOS) IDB PID#: SETTING CLASSIFICATION: Concrete retaining wall OPUS PID: LATITUDE: 43° 21.2' N ( 43.35330) LONGITUDE: 124° 11.5' W (-124.19200) The bench mark is a disk set flush in a 11.06 m (36.3 ft) long concrete retaining wall at the north end of the chipper building, west of an abandoned circular burner foundation, at the north end of the property, 9 m (30 ft) north of the north face of the chipper building, and 7.47 m (24.5 ft) west of the east end of the retaining wall.
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 4 of 5 Station ID: 9432796 PUBLICATION DATE: 06/16/2004 Name: ISTHMUS SLOUGH, COOS BAY OR NOAA Chart: 18587 Latitude: 43° 21.1' N ( 43.35170) USGS Quad: COOS BAY Longitude: 124° 11.5' W (-124.19200) T I D A L D A T U M S Tidal datums at ISTHMUS SLOUGH, COOS BAY based on: LENGTH OF SERIES: 1 MONTH TIME PERIOD: September 1982 - September 1982 TIDAL EPOCH: 1983-2001 CONTROL TIDE STATION: 9432780 CHARLESTON, COOS BAY Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS: MEAN HIGHER HIGH WATER MHHW = 2.665 MEAN HIGH WATER MHW = 2.462 MEAN SEA LEVEL MSL = 1.492 MEAN TIDE LEVEL MTL = 1.437 MEAN LOW WATER MLW = 0.412 MEAN LOWER LOW WATER MLLW = 0.000 North American Vertical Datum (NAVD88) Bench Mark Elevation Information In METERS above: Stamping or Designation MLLW MHW 2796 A 1982 3.887 1.425 2796 B 1982 4.832 2.370 2796 C 1982 3.971 1.509 2796 D 1982 4.678 2.216 2796 E 1982 8.693 6.231
U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Ocean Service Page 5 of 5 Station ID: 9432796 PUBLICATION DATE: 06/16/2004 Name: ISTHMUS SLOUGH, COOS BAY OR NOAA Chart: 18587 Latitude: 43° 21.1' N ( 43.35170) USGS Quad: COOS BAY Longitude: 124° 11.5' W (-124.19200) D E F I N I T I O N S Mean Sea Level (MSL) is a tidal datum determined over a 19-year National Tidal Datum Epoch. It pertains to local mean sea level and should not be confused with the fixed datums of North American Vertical Datum of 1988 (NAVD88). NAVD88 is a fixed datum derived from a simultaneous, least squares, minimum constraint adjustment of Canadian/Mexican/United States leveling observations. Local mean sea level observed at Father Point/Rimouski, Canada was held fixed as the single initial constraint. NAVD88 replaces NGVD29 as the national standard geodetic reference for heights. Bench mark elevations relative to NAVD88 are available from NGS through the World Wide Web at National Geodetic Survey. NGVD29 is a fixed datum adopted as a national standard geodetic reference for heights but is now considered superseded. NGVD29 is sometimes referred to as Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological Survey Topographic Quads. NGVD29 was originally derived from a general adjustment of the first-order leveling networks of the U.S. and Canada after holding mean sea level observed at 26 long term tide stations as fixed. Numerous local and wide-spread adjustments have been made since establishment in 1929. Bench mark elevations relative to NGVD29 are available from the National Geodetic Survey (NGS) data base via the World Wide Web at National Geodetic Survey. NAVD88 and NGVD29 are fixed geodetic datums whose elevation relationships to local MSL and other tidal datums may not be consistent from one location to another. The Vertical Mark Number (VM#) and PID# shown on the bench mark sheet are unique identifiers for bench marks in the tidal and geodetic databases, respectively. Each bench mark in either database has a single, unique VM# and/or PID# assigned. Where both VM# and PID# are indicated, both tidal and geodetic elevations are available for the bench mark listed. The NGS's Integrated Data Base (IDB PID) provides geodetic datum based on traditionally leveled and bluebooked ties to the National Spatial Reference System(NSRS) https://www.ngs.noaa.gov/datasheets/. The NGS Online Positioning User Service (OPUS PID) provides geodetic datum based on GPS position & tie it to the NSRS https://www.ngs.noaa.gov/OPUS/. The NAVD88 elevation is shown on the Elevations of Tidal Datums Table Referred to MLLW only when two or more of the bench marks listed have NAVD88 elevations. The NAVD88 elevation relationship shown in the table is derived from an average of several bench mark elevations relative to tide station datum. As a result of this averaging, NAVD88 bench mark elevations computed indirectly from the tidal datums elevation table may differ slightly from NAVD88 elevations listed for each bench mark in the NGS database.