U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 6
Station ID: 9437954 PUBLICATION DATE: 01/22/2024
Name: NORTH FORK, NEHALEM RIVER
NOAA Chart: 18556 Latitude: 45° 44.0' N ( 45.73380)
USGS Quad: FOLEY PEAK Longitude: 123° 52.6' W (-123.87640)
To reach the tidal bench marks from the intersection of US Highway 101 and the H
Street four way stop signed intersection where 101 turns from the north to the
west, proceed north from the intersection on 7th street for 0.3 km (0.3 mi) to a
slight right hand turn to the NE on to Northfork Road, continue NE on Northfork
road for 2.1 km (1.3 mi) to McDonald Dike Road on the right, turn right and
proceed 50 m (164.0 ft) to the bridge over the Northfork of the Nehalem River.
The bench marks are located along Northfork road and on the east side of the
bridge on McDonald Dike Road. The sensor is located on a single piling on the NW
side of the bridge.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: 7954 A 2017
DESIGNATION: 943 7954 A
MONUMENTATION: Flange-encased Rod VM#: 22352
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 45° 44.0' N ( 45.73317) LONGITUDE: 123° 52.5' W (-123.87433)
The primary bench mark is a flange encased rod set on the north side of Mcdonald
Dike Road, 13.14 m (43.1 ft) SSW of the NW gate post for a ranch access gate,
6.43 m (21.1 ft) north of the centerline of Mcdonald Dike Road, 5.32 m (17.5 ft)
WSW of a utility pole numbered 235586, and 1.46 m (4.8 ft) south of a witness
post. The datum point is set 17 cm (7 inches) below grade, being the top of a
stainless steel rod driven 80 ft (24.4 m) to substantial resistance, in a sleeve
extending to a depth of 3 ft (0.9 m) and encased in a 5 inch PVC pipe with
concrete kick block containing, magnetic material and NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 6
Station ID: 9437954 PUBLICATION DATE: 01/22/2024
Name: NORTH FORK, NEHALEM RIVER
NOAA Chart: 18556 Latitude: 45° 44.0' N ( 45.73380)
USGS Quad: FOLEY PEAK Longitude: 123° 52.6' W (-123.87640)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7954 B 2017
DESIGNATION: 943 7954 B
MONUMENTATION: Bench Mark disk VM#: 22353
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 45° 44.0' N ( 45.73344) LONGITUDE: 123° 52.5' W (-123.87558)
The bench mark is a disk set in the NE wingwall of the Mcdonald Dike Road bridge
over the Northfork of the Nehalem river, 19.30 m (63.3 ft) WNW of the end of a
guardrail, 5.01 m (16.4 ft) NNE of the centerline of Mcdonald Dike Road, 4.87 m
(16.0 ft) WSW of the invert of a storm culvert, and 3.63 m (11.9 ft) west of the
SE corner of the wing wall.
BENCH MARK STAMPING: 7954 C 2017
DESIGNATION: 943 7954 C
MONUMENTATION: Bench Mark disk VM#: 22354
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: OPUS PID:
LATITUDE: 45° 44.0' N ( 45.73386) LONGITUDE: 123° 52.6' W (-123.87689)
The bench mark is a disk set in the NW wingwall of the Mcdonald Dikeroad bridge
over the Northfork of the Nehalem River, 18.29 m (60.0 ft) ESE of a utility pole
numbered 234504, 5.09 m (16.7 ft) NNE of the centerline of Mcdonald Dike road,
4.93 m (16.2 ft) ESE of the center of a vertically placed storm culvert, and
3.60 m (11.8 ft) ESE of the NE wing wall corner.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 6
Station ID: 9437954 PUBLICATION DATE: 01/22/2024
Name: NORTH FORK, NEHALEM RIVER
NOAA Chart: 18556 Latitude: 45° 44.0' N ( 45.73380)
USGS Quad: FOLEY PEAK Longitude: 123° 52.6' W (-123.87640)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 7954 D 2017
DESIGNATION: 943 7954 D
MONUMENTATION: Flange-encased Rod VM#: 22355
AGENCY: National Ocean Service IDB PID#:
SETTING CLASSIFICATION: OPUS PID#: BBFT71
LATITUDE: 45° 44.0' N ( 45.73333) LONGITUDE: 123° 52.6' W (-123.87731)
The bench mark is flange encased rod set on the east side of Northfork Road near
the boundary between address 38205 and the empty lot to the south, 32.60 m
(107.0 ft) SSW of a fire hydrant, 9.33 m (30.6 ft) east of the centerline of
Northfork Road, 6.58 m (21.6 ft) south of a utility pole on the east side of the
road numbered 243503, and 0.33 m (1.1 ft) SW of the east end of a 2 ft (0.6 m)
retaining wall bordering address 38205 and the empty lot to the south. The datum
point is set 5 cm (2 inches) below grade, being the top of a stainless steel rod
driven 42 ft (12.8 m) to substantial resistance, in a sleeve extending to a
depth of 3 ft (0.9 m) and encased in a 5 inch PVC pipe with concrete kick block,
containing magnetic material and NOS logo cap.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 6
Station ID: 9437954 PUBLICATION DATE: 01/22/2024
Name: NORTH FORK, NEHALEM RIVER
NOAA Chart: 18556 Latitude: 45° 44.0' N ( 45.73380)
USGS Quad: FOLEY PEAK Longitude: 123° 52.6' W (-123.87640)
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: PUMP STATION
MONUMENTATION: Survey disk VM#: 22356
AGENCY: Tillamook County IDB PID#:
SETTING CLASSIFICATION: Concrete Pad OPUS PID:
LATITUDE: 45° 43.8' N ( 45.73058) LONGITUDE: 123° 53.0' W (-123.88342)
The bench mark is a disk set in a concrete pad leading to the man door for a
Nehalem Bay Wastewater Agency outbuilding, 15.57 m (51.1 ft) WNW of the
centerline of Northfork Road, 12.21 m (40.1 ft) west of a 2 ft (0.6 m) round
sewer manhole cover, 10.87 m (35.7 ft) WNW of a utility pole numbered 231302,
1.52 m (5.0 ft) north of the NE corner of the pump house building, and 0.43 m
(1.4 ft) WSW of the NE corner of a concrete pad.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 6
Station ID: 9437954 PUBLICATION DATE: 01/22/2024
Name: NORTH FORK, NEHALEM RIVER
NOAA Chart: 18556 Latitude: 45° 44.0' N ( 45.73380)
USGS Quad: FOLEY PEAK Longitude: 123° 52.6' W (-123.87640)
T I D A L D A T U M S
Tidal datums at NORTH FORK, NEHALEM RIVER based on:
LENGTH OF SERIES: 3 MONTHS
TIME PERIOD: July 2017 - September 2017
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION: 9437540 Garibaldi, Tillamook Bay
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
MEAN HIGHER HIGH WATER MHHW = 2.552
MEAN HIGH WATER MHW = 2.340
MEAN TIDE LEVEL MTL = 1.346
MEAN SEA LEVEL MSL = 1.333
MEAN LOW WATER MLW = 0.351
MEAN LOWER LOW WATER MLLW = 0.000
North American Vertical Datum (NAVD88)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
7954 A 2017 3.660 1.320
7954 B 2017 6.468 4.128
7954 C 2017 7.036 4.696
7954 D 2017 5.535 3.195
PUMP STATION 5.237 2.897
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 6
Station ID: 9437954 PUBLICATION DATE: 01/22/2024
Name: NORTH FORK, NEHALEM RIVER
NOAA Chart: 18556 Latitude: 45° 44.0' N ( 45.73380)
USGS Quad: FOLEY PEAK Longitude: 123° 52.6' W (-123.87640)
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.