U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Datums Page Page 1 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
To reach the tidal bench marks from the U.S. Post Office/Bank of Alaska on 6th
and Broadway, proceed SW on Broadway for five blocks, turn NW on First Avenue
and proceed for one block, turn SE on Stage Street and enter the Cypress Anville
Ore Company (private property). Proceed down to the dock area. The bench marks
are located in the general vicinity. The tide gauge is located on the north
section of the intersection between pier and SE/NW running access pier adjacent
to a large ore elavator.
T I D A L B E N C H M A R K S
PRIMARY BENCH MARK STAMPING: NO 11 1969
DESIGNATION: 945 2400 TIDAL 11
MONUMENTATION: Tidal Station disk VM#: 1202
AGENCY: US Coast and Geodetic Survey (USC&GS) PID:
SETTING CLASSIFICATION: Bedrock
The primary bench mark is a disk set in a drill hole flush with the surface of a
projected segment of a bedrock ledge, 49 m (160 ft) SE of the intersection of
the spur line with the main line, 2.74 m (9.0 ft) east of the east rail of the
spur line to the wharf, and 0.79 m (2.6 ft) north of an orange NOS witness post.
BENCH MARK STAMPING: 8 1959
DESIGNATION: 945 2400 TIDAL 8
MONUMENTATION: Tidal Station disk VM#: 1207
AGENCY: US Coast and Geodetic Survey (USC&GS) PID:
SETTING CLASSIFICATION: Boulder
The bench mark is a disk set in the NE end of an 2 m (8 ft) diameter boulder
39.50 m (129.f ft) NE of utility pole B317, 19 m (61 ft) east of the centerline
of the road, 1.52 m (5.0 ft) south of a 9 m x 30 m (30 ft x 100 ft) warehouse,
0.85 m (2.8 ft) SE of an orange NOS witness post, and about 1 m (3 ft) above the
ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 2 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2400 B 1982
DESIGNATION: 945 2400 B
MONUMENTATION: Tidal Station disk VM#: 1210
AGENCY: National Ocean Survey (NOS) PID:
SETTING CLASSIFICATION: Concrete platform
The bench mark is a disk set flush on the SW corner of the White Pass Railroad
passenger terminal loading platform located on First Avenue between Broadway
Street and Spring Street, 5.79 m (19.0 ft) SW of the SW corner of Railroad Depot
Building, 2.07 m (6.8 ft) SE of the most western grey post that supports a steel
roof covering the platform, and 1.83 m (6.0 ft) north of the northern-most
railway rail.
BENCH MARK STAMPING: 2400 E 1991
DESIGNATION: 945 2400 E
MONUMENTATION: Tidal Station disk VM#: 3226
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete foundation
The bench mark is a disk set flush in concrete in the NE corner of the midspan
support for the ore conveyor of the White Pass Ore Terminal, 29.57 m (97.0 ft)
south of the first light pole on the pier, 28.35 m (93.0 ft) west of the west
corner of the tide house, 10.30 m (33.8 ft) east of west edge of a concrete
platform, 1.98 m (6.5 ft) south of the NE corner of the concrete platform, and
0.43 m (1.4 ft) NE of the east corner of the building surrounding the conveyor
structure.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 3 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING:
DESIGNATION: 945 2400 CENTERLINE
ALIAS: NO STAMPING 1
MONUMENTATION: Bench Mark disk VM#: 3227
AGENCY: Alaska Department of Highway PID:
SETTING CLASSIFICATION: Pavement
The bench mark is an unstamped disk located in the center of the intersection of
State Street (Alaska 98) and First Avenue, 13.08 m (42.9 ft) SE of a yellow fire
hydrant, 12.10 m (39.7 ft) ENE from 0.91 m x 0.46 m (3.0 ft x 1.5 ft) storm
drain grate located on First Avenue in the SW corner of the intersection, 11.7 m
(38.3 ft) NW of a storm drain grate located on First Avenue in the SW corner of
the intersection, and 0.24 m (0.8 ft) below ground level under a 0.21 m (0.7 ft)
monument cover with a large M on it.
BENCH MARK STAMPING: 2400 G 1997
DESIGNATION: 945 2400 G
MONUMENTATION: Tidal Station disk VM#: 13746
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: bedrock
The bench mark is a disk set in a bedrock outcropping located east of town, NE
of the White Pass and Yukon Railway junction that switches the tracks to the
railway station or the cruise ship dock, up the path to the east from the trail
head to Dewey Lakes, 24.38 m (80.0 ft) SE of the center of a foot bridge that
crosses Pullen Creek which runs parallel to the tracks, 22 m (73 ft) NE of the
switch box at the railroad junction, 16 m (53 ft) east of the center of the
raiload tracks, 11 m (35 ft) south of the Dewey Lakes trail sign, 3 m (10 ft)
east of center of hiking trail, and 1 m (2 ft) above ground level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 4 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2400 J 1997
DESIGNATION: 945 2400 J
MONUMENTATION: Tidal Station disk VM#: 13748
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: bedrock
The bench mark is a disk set in a bedrock outcropping located east of town, NE
of the White Pass and Yukon Railway junction that switches the tracks to the
railway station or the cruise ship dock, 260 m (853 ft) NE of bench mark 2400 H
1997, 43.10 m (141.5 ft) north of the 6th telephone pole which is north of the
junction, 4.85 m (15.9 ft) SE of the 7th telephone pole which has an attached
NOAA witness marker which is north of the junction, 3.57 m (11.7 ft) NW of enter
of railroad tracks, and 1 m (3 ft) above ground level.
BENCH MARK STAMPING: A 1910
DESIGNATION: 945 2400 A 1910
MONUMENTATION: Tidal Station disk VM#: 16722
AGENCY: US Coast and Geodetic Survey (USC&GS) PID#: TT0050
SETTING CLASSIFICATION: Building
The bench mark is a disk set vertically in the south side of the old city hall
stone building - now a museum - located at the east end of 7th Street, 61 m
(200 ft) west of White Pass & Yukon railway tracks, 4 m (13 ft) south of the
south face of the building, 0.61 m (2.0 ft) north of SE corner midspan of the
building, and 0.75 m (2.5 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 5 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
T I D A L B E N C H M A R K S
BENCH MARK STAMPING: 2400 K 2002
DESIGNATION: 945 2400 K
MONUMENTATION: Tidal Station disk VM#: 16723
AGENCY: National Ocean Service (NOS) PID:
SETTING CLASSIFICATION: Concrete foundation
The bench mark is a disk set flush in a 1.82 m x 1.63 m x 0.25 m (6.0 ft x 5.3
ft x 0.8 ft) concrete foundation block located on the east side of the White
Pass & Yukon Railway warehouse which connects to the ore conveyor, 15 m (49 ft)
SW of second utility pole north of the ore conveyor, 12.71 m (41.7 ft) west of a
yellow & green fire hydrant, 0.30 m (1 ft) east of the warehouse, and 0.25 m
(0.8 ft) above ground.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 6 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
T I D A L D A T U M S
Tidal datums at SKAGWAY, TAIYA INLET based on:
LENGTH OF SERIES: 5 YEARS
TIME PERIOD: January 2002 - December 2006
TIDAL EPOCH: 1983-2001
CONTROL TIDE STATION:
Elevations of tidal datums referred to Mean Lower Low Water (MLLW), in METERS:
HIGHEST OBSERVED WATER LEVEL (10/22/1945) = 7.967
MEAN HIGHER HIGH WATER (MHHW) = 5.100
MEAN HIGH WATER (MHW) = 4.795
MEAN SEA LEVEL (MSL) = 2.683
MEAN TIDE LEVEL (MTL) = 2.644
MEAN LOW WATER (MLW) = 0.493
MEAN LOWER LOW WATER (MLLW) = 0.000
LOWEST OBSERVED WATER LEVEL (01/12/2005) = -1.903
National Geodetic Vertical Datum (NGVD 29)
Bench Mark Elevation Information In METERS above:
Stamping or Designation MLLW MHW
NO 11 1969 10.835 6.040
8 1959 10.556 5.761
2400 B 1982 8.773 3.978
2400 E 1991 8.668 3.873
945 2400 CENTERLINE 8.228 3.433
2400 G 1997 12.538 7.743
2400 J 1997 11.237 6.442
A 1910 10.878 6.083
2400 K 2002 9.044 4.249
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 7 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
Foot Notes:
Areas of Alaska have anomalous relative sea level trends compared to most other
geographic regions in the United States. This is due to a general uplift of the
land in this area, which has been occurring at a rapid rate. Because of the
magnitude of the sea level trends in these areas, NOAA has adopted a procedure
for computing accepted tidal datums for the National Water Level Observation
Network (NWLON) using the last several years of sea level data rather than the
19-year tidal epoch. The tide ranges are still based on the 1983-2001 National
Tidal Datum Epoch (NTDE) and are applied to the 5 year (2002-2006) Mean Tide
Level (MTL) to compute other tidal datums. The adoption of this procedure was
necessary to ensure that these tidal datums accurately represent the existing
stand of sea level.
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
National Ocean Service
Page 8 of 8
Station ID: 9452400 PUBLICATION DATE: 09/17/2007
Name: SKAGWAY, TAIYA INLET
ALASKA
NOAA Chart: 17317 Latitude: 59° 27.0' N
USGS Quad: SKAGWAY B-1 Longitude: 135° 19.6' W
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 (NAVD 88).
NGVD 29 is a fixed datum adopted as a national standard geodetic reference for
heights but is now considered superseded. NGVD 29 is sometimes referred to as
Sea Level Datum of 1929 or as Mean Sea Level on some early issues of Geological
Survey Topographic Quads. NGVD 29 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 NGVD 29 are available from the National
Geodetic Survey (NGS) data base via the World Wide Web at
National Geodetic Survey.
NAVD 88 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. NAVD 88 replaces NGVD 29 as the national
standard geodetic reference for heights. Bench mark elevations relative to
NAVD 88 are available from NGS through the World Wide Web at
National Geodetic Survey.
NGVD 29 and NAVD 88 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 NAVD 88 elevation is shown on the Elevations of Tidal Datums Table Referred
to MLLW only when two or more of the bench marks listed have NAVD 88 elevations.
The NAVD 88 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, NAVD 88 bench mark elevations computed indirectly from the tidal
datums elevation table may differ slightly from NAVD 88 elevations listed for
each bench mark in the NGS database.