Bench Mark Sheet for 9439189, Rocky Point

Superseded Epoch

Large map location marker Station Location
Small red map location marker Published bench mark
Small blue map location marker Unpublished bench mark

Bench mark positions only appear on the map if their coordinates in the CO-OPS database are at the precision of degrees/minutes/seconds/and tenths of seconds. If the coordinates are less precise, the mark will not appear.

Printable version

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  6

                                                                                
Station ID: 9439189                         PUBLICATION DATE:  02/13/2012
Name:       ROCKY POINT, MULTNOMAH CHANNEL                    
            OR
NOAA Chart: 18525                           Latitude:   45° 41.8' N (  45.69670)
USGS Quad:  SAUVIE ISLAND                   Longitude: 122° 52.1' W (-122.86800)


To reach the tidal bench marks from Scapoose Post Office, proceed south on
Highway 30 for 6 km (4 mi) to milepost 16.8, then turn left and proceed 0.16 km
(0.1 mi) ESE down the hill and across the railroad tracks on lower Rocky Point
Road, then bear a sharp left and proceed 0.16 km (0.1 mi) north to the Rocky
Point Parking lot.  The bench marks are located along the east side of Highway
30.  Two bubbler gauges were housed in the attic of the Rocky Point Marina
store.  Orifices were mounted on iron pipes welded to the dock pilings.


                         T I D A L   B E N C H   M A R K S
                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  6

                                                                                
Station ID: 9439189                         PUBLICATION DATE:  02/13/2012
Name:       ROCKY POINT, MULTNOMAH CHANNEL                    
            OR
NOAA Chart: 18525                           Latitude:   45° 41.8' N (  45.69670)
USGS Quad:  SAUVIE ISLAND                   Longitude: 122° 52.1' W (-122.86800)


                         T I D A L   B E N C H   M A R K S


                 PRIMARY BENCH MARK STAMPING:  S 101 1932
                         DESIGNATION:          S 101

MONUMENTATION:           Bench Mark disk                       VM#:        17462
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  RD0546
SETTING CLASSIFICATION:  Concrete post                         OPUS PID:        
LATITUDE:   45° 41.9' N (  45.69830)          LONGITUDE: 122° 52.2' W (-122.87000)


The primary bench mark is a disk set in a 0.25 m (0.8 ft) diameter concrete
post, 41 m (134 ft) east of the centerline of Highway 30, 9.4 m (30.8 ft) NE of
the centerline of a paved road leading to the marina, 1.85 m (6.1 ft) WNW of the
center of the west trunk of a double oak tree, 0.23 m (0.7 ft) north of a metal
USC&GS witness post and sign, and 6 cm (0.2 ft) below the surface.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  6

                                                                                
Station ID: 9439189                         PUBLICATION DATE:  02/13/2012
Name:       ROCKY POINT, MULTNOMAH CHANNEL                    
            OR
NOAA Chart: 18525                           Latitude:   45° 41.8' N (  45.69670)
USGS Quad:  SAUVIE ISLAND                   Longitude: 122° 52.1' W (-122.86800)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:   
                         DESIGNATION:          B 30

MONUMENTATION:           Spike                                 VM#:        17463
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  RD0547
SETTING CLASSIFICATION:  Concrete retaining wall               OPUS PID:        
LATITUDE:   45° 41.8' N (  45.69670)          LONGITUDE: 122° 52.2' W (-122.87000)


The bench mark is a railroad spike set near the bottom of an old nearly vertical
concrete retaining wall, 96 m (315 ft) south of the centerline of the railroad
crossing, 42.88 m (140.7 ft) SSE of a wooden light pole, 27.61 m (90.6 ft) SSW
of power pole #36J882 east of the railroad, 3.04 (10.0 ft) east of the
centerline of the railroad, 0.40 m (1.3 ft) north of the southern end of the
wall, 1.81 m (5.9 ft) below the lower top lip of the concrete retaining wall,
and 0.38 m (1.2 ft) above the bottom of the concrete retaining wall.



                         BENCH MARK STAMPING:  9189 A 2003
                         DESIGNATION:          943 9189 A TIDAL

MONUMENTATION:           Tidal Station disk                    VM#:        17464
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Rock outcrop                          OPUS PID:        
LATITUDE:   45° 41.7' N (  45.69500)          LONGITUDE: 122° 52.2' W (-122.87000)


The bench mark is a disk recessed in a small rock outcrop on the east side of
the railroad tracks, 231 m (758 ft) south of the railroad crossing at Rocky
Point Marina, 10.2 m (33.5 ft) WNW of the centerline of a paved access road to
Happy Rock Moorage, 3.8 m (12.5 ft) ESE of the centerline of the railroad
tracks, 3.8 m (12.5 ft) SW of the high point of isolated rock outcrop, and flush
with the rock outcrop.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  6

                                                                                
Station ID: 9439189                         PUBLICATION DATE:  02/13/2012
Name:       ROCKY POINT, MULTNOMAH CHANNEL                    
            OR
NOAA Chart: 18525                           Latitude:   45° 41.8' N (  45.69670)
USGS Quad:  SAUVIE ISLAND                   Longitude: 122° 52.1' W (-122.86800)


                         T I D A L   B E N C H   M A R K S


                         BENCH MARK STAMPING:  9189 B 2003
                         DESIGNATION:          943 9189 B TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        17465
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   45° 42.3' N (  45.70500)          LONGITUDE: 122° 52.3' W (-122.87200)


The bench mark is located 23.12 m (75.9 ft) south of a wooden light pole
#26H279, 11.70 m (38.4 ft) east of the eastern fog line of Highway 30, 10.8 m
(35.4 ft) south of the centerline of Lower Rocky Point Road, and 2.52 m (8.3 ft)
SE of a guardrail.  The bench is set flush with the ground, being the top of a
rounded off stainless steel rod in a sleeve extending to a depth of 1 m (3 ft),
with punch mark, driven 4.0 m (13.1 ft) to refusal, and encased in a PVC pipe
with concrete kick block and NGS Geodoetic Control Mark logo cover.



                         BENCH MARK STAMPING:  9189 C 2003
                         DESIGNATION:          943 9189 C TIDAL

MONUMENTATION:           Flange-encased Rod                    VM#:        17466
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Stainless steel rod in sleeve         OPUS PID:        
LATITUDE:   45° 42.3' N (  45.70500)          LONGITUDE: 122° 52.3' W (-122.87200)


The bench mark is located 20.79 m (68.2 ft) SW of the nearest edge of an oak
tree with triple trunk, 16.50 m (54.1 ft) east of the eastern fog line of
Highway 30, 0.96 m (3.1 ft) west of a barbed wire fence, and approximately 2.5 m
(8 ft) below Highway 30. The bench is set 9 cm (0.3 ft) below grade, being the
top of a rounded off stainless steel rod in a sleeve extending to a depth of 1 m
(3 ft), with punch mark, driven 14.5 m (48 ft) to refusal, and encased in a PVC
pipe with concrete kick block and NGS Geodoetic Control Mark logo cover.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  6

                                                                                
Station ID: 9439189                         PUBLICATION DATE:  02/13/2012
Name:       ROCKY POINT, MULTNOMAH CHANNEL                    
            OR
NOAA Chart: 18525                           Latitude:   45° 41.8' N (  45.69670)
USGS Quad:  SAUVIE ISLAND                   Longitude: 122° 52.1' W (-122.86800)


                            T I D A L   D A T U M S 


Tidal datums at ROCKY POINT, MULTNOMAH CHANNEL based on:

     LENGTH OF SERIES:      9 MONTHS
     TIME PERIOD:           Aug 04-Oct 04; Aug 05-Oct 05; & Aug 06-Oct 06
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9439040 ASTORIA, TONGUE POINT, COLUMBIA RIVER


Elevations of tidal datums referred to Columbia River Datum (-2), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  1.571
     MEAN HIGH WATER                            MHW    =  1.399
     MEAN TIDE LEVEL                            MTL    =  1.014
     MEAN SEA LEVEL                             MSL    =  0.994
     MEAN LOW WATER                             MLW    =  0.630
     MEAN LOWER LOW WATER                       MLLW   =  0.560
     a River Datum (-2)                       Columb =  0.000

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    -2          MHW

     S 101 1932                                 21.391   19.992
     B 30                                       10.188    8.789
     9189 A 2003                                10.023    8.624
     9189 B 2003                                28.748   27.349
     9189 C 2003                                13.313   11.914


Foot Notes:

Data were collected on Columbia River Datum (CRD).  Datums were computed using
data from three months of lowest river levels, generally the months
August-October over multiple years.  Depending on river flow, water levels can
be significantly higher than Columbia River Datum.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  6

                                                                                
Station ID: 9439189                         PUBLICATION DATE:  02/13/2012
Name:       ROCKY POINT, MULTNOMAH CHANNEL                    
            OR
NOAA Chart: 18525                           Latitude:   45° 41.8' N (  45.69670)
USGS Quad:  SAUVIE ISLAND                   Longitude: 122° 52.1' W (-122.86800)


                             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.

Return to Top
Products available at 9439189 Rocky Point,