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INTRODUCTION
Yellow Island, San Juan County, WA, is currently owned by The
Nature Conservancy (TNC), who actively manages its vegetative
land cover through restoration plantings, plant removal, and
occasional prescribed burning in order to favor some species
over others. In part, TNC's management efforts are informed by
an understanding of the conditions and processes that existed
prior to Euro-American settlement in the archipelago. It is well
to recall that such non-native settlement of the San Juans began
in earnest only after the General Land Office survey of 1874
(which omitted Yellow Island). Until the mid-1900s, settlement
impact on Yellow Island was indirect, namely by cessation of
native visitations. Present and historic conditions on Yellow
Island were systematically studied by Agee and Dunwiddie (1984).
They inventoried the plant communities, performed age analyses
on trees, and documented evidence of past fires based on fire
scars. Certain conclusions in that study about the sparseness
of the pre-settlement forest were corroborated by a lone 1909
photograph from McConnell Island.
Recently three unpublished images of Yellow
Island, all dated 1895, were discovered and retrieved from the
National Archives. They include a detailed land-cover map called
a T-sheet and two associated photographs, which together constitute
the earliest direct documentation of the island's large vegetation.
These new images now assist in the on-going efforts to document
and understand the vegetation dynamics on Yellow Island.
TOPOGRAPHIC SHEET #2229
T-2229 is one of fifteen manuscript topographic sheets from 1888-1897
covering all of the San Juan Islands (Fig. 1). They were prepared
by J.J. Gilbert of the U.S. Coast and Geodetic Survey, based
on plane-table surveying technology (Fig. 2). These exquisitely
detailed documents represent the earliest systematic documentation
of the topography, land-cover, and cultural features of the San
Juans. Yellow Island appears on T-sheet #2229, which was drafted
in 1895 (USC&GS, 1895a) (Fig. 3); the N-S axis is tilted
40° in order to fit the area of coverage onto a sheet of
tracing fabric measuring 2.7 by 4.8 ft.
T-sheets for the San Juans were never published
or circulated, so they are little known today and their rich
historic content has remained unexamined. Steps to gain broader
accessibility began in 2000 when the original T-sheets of the
San Juans were photocopied at full scale at the National Archives
and Records Administration (NARA II) in College Park, MD. The
retrieved hardcopies were then electronically scanned at 400
ppi and eventually posted on the World Wide Web (WSU, 2002).
On the full-size T-sheet #2229 (Fig. 3) the 1800-ft long axis
of Yellow Island measures about
2.25 in, and numerous topographical features
are indicated. The island's intertidal character is depicted
as rocky and sandy; and the distribution of offshore kelp beds
is also indicated. Inland relief is marked by topographic lines
at 20-ft intervals.At the island's highest point (about 60 ft)
a dotted triangle indicates a triangulation station used in the
survey; it is identified as Signal Goose. Another triangulation
point at the NE point is not marked but is identified as Signal
Yellow (Fig. 4). At such triangulation points braced poles
were erected and typically 2-in holes were bored in the rock
as lasting locators; the surveying crew likely passed some hours
at these locations to make plane-table triangulations and to
record and render observations. Signals Goose and Yellow
would have afforded reasonable views of most of the vegetation
on the island in 1895.
In Figure 3, vegetative land cover is depicted
by standard cartographic symbols: splays of upright ticks for
grass, C-shaped marks for deciduous vegetation (usually meaning
trees or large shrubs), and 5-lined stars for coniferous trees.
These hand-drawn symbols may signify individual trees or clusters
of such vegetation. Most of the ~23 symbols for conifers form
an array coursing from SSW to NNE across the middle of the island;
a cluster of three stars is located at the NE point and single
stars are located near the western point and just north of Signal
Goose. Most of the symbols for deciduous trees are scattered
over the western half of the island.
PHOTOGRAPHS
Along with his surveying activity that produced the T-sheets,
J.J. Gilbert also prepared hand-written narrative reports with
each T-sheet, and some of those included landscape photographs
or drawings. Two photographic images of Yellow Island printed
by a brown bromide-process were pasted into the Descriptive Report
for T-2229 (USC&GS,1895b).
At NARA II in May, 2002, the original prints
were electronically scanned at 300 ppi in black and white; the
versions presented here have been digitally enhanced and sepia-tinted.
The photographic negatives have not been located.
The view point of one scene (Fig. 4) is from the surveyors' boat
in Middle Channel between San Juan and Yellow Islands. A note
indicates that the view is to the NE, but it is more likely ESE,
in which case Shaw Island is the landmass in the background.
The view point of the second photograph (Fig. 5a,b) is from Neck
Point, Shaw Island, nearly a mile from Yellow Island, and is
oriented WNW; San Juan Island and other marked islands lie in
the background; it has been rephotographed (Fig. 5c).
The two 7-inch wide photographic prints included with the narrative
report for Yellow Island in the Descriptive Report for T-2229
are reproduced at slight reductions in Figures 4a and 5a. Signals
Yellow and Goose are clearly indicated by braced
white poles in Figure 4; Signal Yellow is barely discernible
on the right in Figure 5. Image quality is sufficient, especially
in the enlargements, to reveal that ~23 coniferous trees occupied
the island in 1895; most were modest in stature, four or
five were quite tall, and one was a
tall snag. Shrubs and small trees are also indicated but cannot
be clearly identified. A brief text entry (below) by J.J. Gilbert
in Descriptive Report T-2229 supports impressions of the island's
vegetation gained from the photographs and T-sheet:
"Yellow Island.the westernmost
of the Wasp Islands, and locally known as Goose Island, is rocky
and rather sparcely (sic)
covered with willow and other brush and a few scattering fir
trees. Off the west end
are several reefs, mostly covered at low tide. There is anchorage
for a launch or other small craft on the north side of the spit
at west end of island." (USC&GS,
1895b, p. 9; emphasis added).
DISCUSSION
According to J.J. Gilbert's narrative description, the associated
photographs, and the cartographic details of T-sheet #2229, the
large vegetation of Yellow Island in 1895 was sparse, composed
of both deciduous and coniferous forms, and located primarily
near the center of the island. The recently rephotographed profile
of the island from Shaw Island (Fig. 5c) illustrates some of
the changes in large vegetation that have occurred over a span
of 107 years. Compared to 1895, the average forest canopy (or
"skyline") is now taller, the forest zone is broader
and denser in terms of foliage and number of trees, and large
spherical masses of opaque foliage indicative of deciduous forms
are prominent today, at least facing the SE. The tallest trees
in 1895 and 2002 are about the same height, but the number of
tall trees is now greater. The tall snag a century ago and the
solitary tall tree at the right in Figure 5b are no longer present.
Figure 6. Aerial photographs of Yellow
Island from 1946 to 2006. Images are sized to correspond
to Figure 3. N-S axis is vertical in (a), (b), and (d).
Further insights into vegetation changes
might benefit from comparisons with additional images, for example,
from times between 1895 and the present. Figure 6a depicts vegetation
on Yellow Island in 1946, which is a published aerial photograph
in the soil survey for San Juan County (USDA, 1962); this published
image is admittedly inferior in quality and somewhat obscured
by overlays of soil polygons, their designations, and V-shaped
symbols signifying rock outcrops. Dark amorphous images
of major vegetation are clearly confined to a swath across the
island's middle. Efforts to obtain superior prints of this photograph
or to locate its negative were unrewarded.
Fairly recent aerial photographs, such as from the 1990 WDNR
series (Fig. 6b) or the 1995 WDOE series (Fig. 6c), more clearly
reveal the present-day distribution of vegetation. According
to these images, large vegetation meaning trees and shrubs
have expanded laterally from the narrower central swath
seen in 1946. Quite recently (Fig. 6d), however, from the online
source Digital Globe (see tagzania.com website), the zone occupied
by large trees and shrubs has been reduced by aggressive management,
that is tree removal.
Figure 7. Summary of zones occupied by
major trees and shrubs from 1895 to 2006.
A rough summary of vegetation changes from
1895 to the present is shown graphically in Figure 7, which is
derived from data in Figures 3, and 6a-c. The sequence indicates
that up to 1990 the area of forest coverage progressively doubled
during each 50-year period by encroaching laterally into grassy
meadows. These changes concur with the findings reported by Agee
and Dunwiddie (1984). Since 1990, however, thanks to TNC's active
management and removal of many trees, the zone occupied by trees
has been reduced to the condition that existed in about 1946.
Removal of even more trees may be required to restore the vegetation
condition reported in the 1895 images, which are here reported
for the first time.
REFERENCES
Agee, J.K. and P.W. Dunwiddie (1984). Recent forest development
on Yellow Island, San Juan County, WA. Can. J. Bot. 65: 2074-2080.
Digital Globe (2006). Online URL: www.
tagzania.com.
U.S. Coast and Geodetic Survey (1895a). Topographic Sheet No.
2229: Topography of Washington Sound, Wash. Orcas and Other Islands.
Section XI, Sheet No. 8 (1:10,000).
National Archives and Records Administration, (Cartographic Division,
Record Group 23), College Park, MD.
U.S. Coast and Geodetic Survey (1895b). Descriptive Report, Sheet
No. 2229. Topography of Washington Sound (by J.J. Gilbert). National
Archives and Records Administration, (Cartographic Division,
Record Group 23), College Park, MD. 18 pp; 14 photographs.
U.S. Geological Service (1941). Aerial photographs of San Juan
County, Washington (B&W; 1:34,000). (Symbol S, Rolls 1-5,
Cans #2985-2989). National Archives and Records Administration,
(Cartographic Division, Record Group 23), College Park, MD.
U.S. Department of Agriculture (1962). Soil Survey: San Juan
County, Washington (by F.E. Schlots, et al.), 73 pp.
Washington State University (2002). See online URL: www.wsulibs.wsu.edu/holland/masc,
select "Digital Collection," under "Northwest
History" select "Early Washington Maps," and finally
select
"Historic Maps of San Juan Islands (1887-1895)." By
selecting an individual map from the index a thumbnail image
will appear. Click on the thumbnail to view an intermediate-size
image; to enlarge the image further, first scroll down to the
bottom of the thunbnail and click "View Map Image"
in order to zoom in for a closer look. Activate the zooming function
by clicking on the specific area of map that interests you, but
take note at this stage whichever detail of the intermediate-size
map is clicked will be the portion that is zoomed. Navigating
laterally beyond the zoomed image is not possible, so to move
to another zoomed area one must first backtrack to the intermediate
image and activate another detail. In 2003 the same T-sheets
(including their Descriptive Reports) were posted on another
URL: http://riverhistory.ess.washington.edu/tsheets/framedex.htm
; when this page opens select a red button for the desired location,
select "Original Scanned Image," and proceed as above
to zoom into a selected portion of the image.
Washington Department of Ecology (1995). Shoreline Aerial Photographs:
SNJ1362, 9/23/1995, 12:14:00 PM, Yellow Island (color; oblique).
On-line URL: apps.ecy.wa.gov/shorephotos/maps.htm
Washington Department of Natural Resources (1990). Aerial photographs:
San Juan County, Washington (B&W). Electronic files.
Washington Department of Natural Resources (2002) See online
URL: www.wa.gov/dnr/htdocs/ adm/comm/nr02-54.htm
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