U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
Datums Page                                                        Page  1 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


The reach the station from the intersection of US Highway 101 and Oregon State
Highway 202 (Nehalem Hwy) proceed east on Highway 202 for 7.7 km (4.8 mi) to the
intersection with Haven View Drive, turn right on Haven View Drive and proceed S
for 0.3 km (0.2 mi) to the end of the road at property 91340 Haven View Drive.
The station is located at the private property dock. The benchmarks are located
on the private property and north 0.5 km (0.2 mi) along Oregon State Highway
202.


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


                 PRIMARY BENCH MARK STAMPING:  8772 A 2013
                         DESIGNATION:          943 8772 A

MONUMENTATION:           Tidal Station disk                    VM#:        20804
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Large round concrete cistern          OPUS PID#: BBDC26
LATITUDE:   46°  7.5' N (  46.12439)          LONGITUDE: 123° 48.2' W (-123.80272)


The bench mark is a disk set in the NW side of a round 9.0 M (29.5 FT) diameter
by 2.45 M (8.0 FT) tall cement tank at the S end of the property, 21.82 M (71.6
FT) SSE of S corner of the red barn, 18.79 M (61.6 FT) SSE of the E corner of a
0.85 M (2.8 FT) tall foundation wall, 5.12 M (16.8 FT) SSW of the S corner of a
galvanized corrugated barn and 1.09 M (3.6 FT) WSW of the W corner of NW drain
grate which is 0.70 M (2.3 FT) by 1.07 M (3.5 FT) in size.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  2 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


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


                         BENCH MARK STAMPING:  8772 B 2013
                         DESIGNATION:          943 8772 B

MONUMENTATION:           Tidal Station disk                    VM#:        20805
AGENCY:                  National Ocean Service (NOS)          IDB PID#:        
SETTING CLASSIFICATION:  Concrete mat pad                      OPUS PID:        
LATITUDE:   46°  7.5' N (  46.12472)          LONGITUDE: 123° 48.2' W (-123.80328)


The bench mark is a disk set in a concrete slab NW of a large galvanized shop
building, 255.7 m (839 ft) SSW of bench mark T 193, 35.84 m (117.6 ft) SSE of
the brick corner of the main residence, 21.62 m (70.9 ft) SSW of a power pole,
14.97 m (49.1 ft) NW of a center post of the large galvanized shop and 0.25 m
(0.8 ft) SE of the NW corner of the slab.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  3 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


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


                         BENCH MARK STAMPING:  79 T 193 1927
                         DESIGNATION:          T 193

MONUMENTATION:           Bench Mark disk                       VM#:        20806
AGENCY:                  Utility company                       IDB PID#:  SC0636
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   46°  7.6' N (  46.12689)          LONGITUDE: 123° 48.1' W (-123.80208)


The bench mark is a disk set in a concrete post, 255.7 m (839 ft) NNE of bench
mark 943 8772 B, 13.74 m (45.1 ft) NNW of a utility pole numbered 147, 7.72 m
(25.3 ft) NNE of the centerline of State Highway 202, 2.84 m (9.3 ft) WNW of the
centerline of a driveway, 2.37 m (7.8 ft) E of a utility pole numbered 147A2 and
about 0.09 m (0.3 ft) above the ground.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  4 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


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


                         BENCH MARK STAMPING:  LEAHY 1935 23
                         DESIGNATION:          LEAHY

MONUMENTATION:           Triangulation Station disk            VM#:        20807
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  SC0633
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   46°  7.7' N (  46.12828)          LONGITUDE: 123° 48.4' W (-123.80708)


The bench mark is a disk set in a concrete post on the S side of the road, 21.05
m (69.1 ft) W of bench mark LEAHY RM 1, 18.00 m (59.1 ft) SSE of a utility pole
numbered 0809 334103, 10.32 m (33.9 ft) WSW of the centerline of Highway 202,
6.35 m (20.8 ft) WSW of the edge of the pavement, 0.55 m (1.8 ft) SSE of a
witness post and set in the top of a 30-cm (12 inch) concrete post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  5 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


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


                         BENCH MARK STAMPING:  NO 2 1935
                         DESIGNATION:          LEAHY RM 2

MONUMENTATION:           Reference Mark disk                   VM#:        20808
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  SC0634
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   46°  7.7' N (  46.12814)          LONGITUDE: 123° 48.4' W (-123.80700)


The bench mark is a disk set in a concrete post on the S side of the road, 23.74
m (77.9 ft) SW of bench mark LEAHY RM 1, 15.78 m (51.8 ft) WNW of a power pole
numbered 0809 334102, 13.64 m (44.8 ft) SW of the centerline of Highway 202,
9.67 m (31.7 ft) SW of the edge of the pavement, 0.363 m (1.2 ft) NNE of a
witness post and set in the top of a 30-cm (12 inch) square concrete post.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  6 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


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


                         BENCH MARK STAMPING:  NO 1 1935
                         DESIGNATION:          LEAHY RM 1

MONUMENTATION:           Reference Mark disk                   VM#:        20809
AGENCY:                  US Coast and Geodetic Survey
                         (USC&GS)                              IDB PID#:  SC0635
SETTING CLASSIFICATION:  Concrete monument                     OPUS PID:        
LATITUDE:   46°  7.7' N (  46.12831)          LONGITUDE: 123° 48.4' W (-123.80683)


The bench mark is a disk set in a concrete post on the N side of the road. It is
40.16 m (131.8 ft) WNW of the NW corner of a shed at property 91195 Highway 202,
24.52 m (80.4 ft) N of a power pole numbered 0908 334102, 17.30 m (56.8 ft) SW
of the edge of the lawn at property 91195 Highway 202, 8.15 m (26.7 ft) NE of
the centerline of Highway 202, 6.54 m (21.5 ft) NE of edge of a bluff leading
down to the road and about 4.05 m (13.3 ft) higher than the road.

                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  7 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


                            T I D A L   D A T U M S 


Tidal datums at CATHCART LANDING, YOUNGS RIVER based on:

     LENGTH OF SERIES:      4 MONTHS
     TIME PERIOD:           June 2013 - September 2013
     TIDAL EPOCH:           1983-2001
     CONTROL TIDE STATION:  9439040 ASTORIA, TONGUE POINT, COLUMBIA RIVER


Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:

     MEAN HIGHER HIGH WATER                     MHHW   =  2.692
     MEAN HIGH WATER                            MHW    =  2.480
     MEAN SEA LEVEL                             MSL    =  1.418
     MEAN TIDE LEVEL                            MTL    =  1.415
     MEAN LOW WATER                             MLW    =  0.349
     MEAN LOWER LOW WATER                       MLLW   =  0.000
     North American Vertical Datum              NAVD88 = -0.021

North American Vertical Datum (NAVD88)

Bench Mark Elevation Information                In METERS above:

     Stamping or Designation                    MLLW        MHW

     8772 A 2013                                10.650    8.170
     8772 B 2013                                11.614    9.134
     79 T 193 1927                              25.561   23.081
     LEAHY 1935 23                               8.184    5.704
     NO 2 1935                                   8.881    6.401
     NO 1 1935                                  11.321    8.841


                          U.S. DEPARTMENT OF COMMERCE
                National Oceanic and Atmospheric Administration
                            National Ocean Service
                                                                   Page  8 of  8

                                                                                
Station ID: 9438772                         PUBLICATION DATE:  02/06/2014
Name:       CATHCART LANDING, YOUNGS RIVER                    
            OR
NOAA Chart: 18521                           Latitude:   46°  7.5' N (  46.12425)
USGS Quad:  OLNEY                           Longitude: 123° 48.3' W (-123.80433)


                             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.