Eagle Lake Field
Station and Environs:
by Dr. Peter B. Moyle, UC, Davis
revised in 2003 by Raymond J.
Bogiatto, Station Manager, CSU,
Chico
The
Eagle Lake Field Station (ELFS) is a collection of wooden, tin-roofed buildings
by Eagle Lake, in remote Lassen County.
The buildings are scattered about an old beach terrace but are largely
hidden from the lake by a sparse grove of Jeffrey pine and western
juniper. The original buildings
were constructed over a period of several years, mostly by faculty, staff and
students from California State University, Chico, so they have a summer cabin
look and feel. They keep out the
elements to some degree, but not entirely. The local wildlife is often as at home in them as the people
who use them on a more temporary basis: deer mice, ground squirrels, bats,
house wrens, barn swallows, and many others. Yet the buildings are quite comfortable and function well
for their intended purpose, which is to get students and faculty together in an
isolated context where natural, rather than anthropomorphic, features dominate
the landscape.
The
building closest to the lake, Vesta Holt Hall, is the principal laboratory
(2100 ft2) for teaching and research, with five rooms in linear
array. Table and bench space is
sufficient for sorting samples fresh from the field or for setting up simple
experiments. Power, water, and a
limited amount of space is available for anyone needing to set up more
sophisticated electronic equipment. A short distance from the laboratory
building is a second building, Bob Ediger Hall (1400 ft2),
containing a library in one half and compact dormitory space in the other. The library is a quiet collection of
desks and tables surrounded by shelves containing several thousand books,
journals, and reprints. The library also serves as a lecture hall and study
area for ELFS user groups.
A
short distance from the library building is the 1300 ft2 dining hall
with its functional, well equipped kitchen. The dining room is the meeting place for large gatherings,
for card or cribbage games, for letter writing, for conversation, for study, or
even for playing a polished, if off-key piano. Adjacent to the dining hall is the 1800 ft2
dormitory building, Shepherd Hall, a barracks style building with two large
rooms. Each room holds 12 cots,
thinly partitioned from one another, and is equipped with electricity, hot
running water, 2 bathrooms, and 2 showers.
Nearby,
in a cluster, are five cabins for faculty, staff, special visitors, and
long-term researchers. One of the
best of them is the winterized, two story A-frame cabin, Omicron Cabin,
inhabited by the resident Steward and Cook. This 900 ft2 cabin is quite comfortable and
homey. Around the A-frame are
three additional full-sized cabins, Alice Stone, Theta, and Epsilon Cabins,
each about 400 ft2, with a bedroom, bathroom, and kitchen/living
area. The furniture and appliances (electric) are of a variety of vintages,
some old and some new, yet quite functional. The atmosphere in the cabins is that of a place where you do
not hesitate to take off your boots, toss them in a corner, and put your feet
up. The roofs keep the rain off
and the windows intercept the light and the lake breezes. In short, the cabins are old-shoe
comfortable. Other buildings
about the place include a small 142ft2 cabin (Roger Lederer Cabin)
with a single bed, a small living space, and a bathroom (without a shower), a
wash house with a washer and dryer for station staff, a storage shed, and a
Quonset Hut which serves as both a garage and the Steward's repair shop. In
addition, a new 1500 ft2 Conference Center, with a deck that
overlooks the lake, was added to the ELFS in 1999.
The
buildings of the field station are centered on a 63 acre plot of mixed forest
of Jeffrey pine, western juniper, mountain mahogany, Great Basin sage, and gray
rabbit brush. The original 23 acre
parcel was purchased from the U.
S. Bureau of Land Management (BLM) in 1964 by students and faculty of Omicron
Theta Epsilon, the CSU, Chico Biological Sciences Honor Society. An additional 40 acre parcel was
subsequently purchased from the BLM in 1970; the ELFS property is currently
surrounded by both private and BLM land.
The field station parcel has been divided up into a permanent grid
of 50m squares, using numbered
steel posts, to facilitate long-term field studies.
Although
the buildings of the station make it an attractive, functional facility,
perhaps its most desirable feature is its isolation. It is a one hour drive to Susanville, the nearest town, and
16 km from the nearest paved road.
The 16 km is a long 16 km because much of it is unimproved dirt road,
barely passable by passenger cars during the dry summer and sometimes requiring
a four wheel drive vehicle in winter.
There are no public telephones at the field station although a phone is
available in case of emergency.
The nearest neighbor to the station is the Lassen County Youth Camp
about one km to the north.
Otherwise, the station is surrounded by wild lands and a wild lake.
The
most spectacular part of the station environment is, of course, Eagle Lake
itself, with its large expanse of clear, frequently turbulent, water. The shore of the lake near the station
is made up of a mixture of basalt boulders, smooth pebbles, and granitic
sands. There is enough sand in
places to land a boat in quiet weather and plenty of large boulders to smash
the keel of an untethered boat in windy weather. To the south of the station is a long, privately owned sandy
beach, one of the best on the lake.
The beach is divided by a short canal that leads to the now-blocked Bly
Tunnel through the basalt ridge to the east. The canal and tunnel were part of a 1920's scheme to siphon
off Eagle lake water to irrigate the Honey Lake Valley. The scheme failed, primarily because
lake levels dropped too low for diversion during a long 1930's drought. Now blocked off, tunnel seepage
continues to help keep Eagle Lake from rising to its former levels. This tunnel seepage manages to augment
the flow down Willow Creek, about 3km east of the station. A more effective plug was installed in
Bly Tunnel in August 1986, but the BLM still maintains relatively constant
water releases through a control structure at the site of the new plug. The channel leading to the closed
tunnel is deep (3-4m) and clear.
It is usually full of tui chubs, Lahontan redsides, and Tahoe suckers,
which makes for interesting snorkeling.
Beyond the channel and sandy beach, the lake shore rises steeply on the
basalt covered slopes of Black Mountain, a prominent feature of the shoreline.
North
of the station, the shoreline becomes increasingly rocky, until it becomes a
solid outcropping of large geometrical lava boulders. In the strong afternoon winds, the waves smash against the
black rocks and gulls cry overhead, so the feeling is more like being on the
North Coast rather than at 1570m above sea level on the Modoc Plateau. Continuing along the shoreline past the
youth camp, one eventually comes to a sagebrush covered point that projects
into the middle basin of the lake.
In the lee of this point are large beds of hard-stemmed bulrush and
rocky beaches that serve as roosting, nesting, and foraging areas for many water
birds. Behind these beaches, over
a low ridge, is a meadow/marsh system, the south end of which is just a short
walk from the station. This marsh,
an extension of the old lake basin, is a breeding area for waterfowl, as well
as black terns, Wilson's phalaropes, and yellow-headed blackbirds during high
water years. The marsh is
surrounded by sagebrush-covered flats, the home of California kangaroo rats and
Great Basin pocket mice. On nearby
trees, power poles, and cabins are at least 6 active osprey nests, conspicuous
as large, untidy piles of sticks defended with whistles and screams by these
fish-eating raptors.
To
the east of the station is a steep ridge of basalt boulders, partly overgrown,
that must have once marked an old shoreline. At one location, near the station's well, there is a deep
overhang of rock (partially boarded up during the 1920's and used as a storage
area and even as living quarters for workers of the Bly Tunnel Project) in
which hundreds of small bats, western pipistrels, hang out during the summer
and fall months. The tangle
of boulders, trees, and shrubs on the ridge is an ideal habitat for small
mammals which are abundant there.
The large piles of sticks created by woodrats are common, as are the
white ridges of dried rat urine (urinite) on conspicuous rocks that have been
marked repeatedly by generations of rats.
The ridge rises up into large tracts of second growth mixed conifer
forest, home to mule deer and other forest wildlife.
The
summer climate of the ELFS is quite pleasant, with warm days and cool
nights. When it starts getting
warm in the afternoon, the breeze from the lake is refreshing. In winter, it stays cold enough for
long enough to cause ice to form on the surface of the lake, in most
years. Snowfall and snow
accumulation is generally light, although cross-country skiing is occasionally
possible. The air is clear so the
night skies are spectacular.
Because the station faces west, the sun sets across the lake, providing
an aesthetically pleasing experience
every evening.
Eagle
Lake is, behind Lake Tahoe, Clear Lake, and Goose Lake, the largest freshwater
lake in California. It has a
surface area of around 11500ha (although this fluctuates) and is about 22km
long and 4-7km wide. Its drainage
basin is relatively small, about 1500 square kilometers. Eagle Lake consists of three
interconnected basins, each with its own limnological characteristics. In all, however, the water is clear -
the bottom can usually be seen at 4-6m - and cool, rarely exceeding 20 degrees
Celsius, except near the surface on calm days. The northern two basins are comparatively shallow (6-10m)
and surrounded by sage-covered hills, while the larger southern basin (on which
the station is located) is much deeper (to 30m). Despite daily winds, the southern basin usually thermally
stratifies each summer. The
productivity of the lake is impressive.
Caddisflies, mayflies, and aquatic moths may hatch at times in enormous
numbers, carpeting the surface of the lake on calm mornings. Zooplankton may "bloom" in
such numbers that they are clearly visible to the naked eye, especially swarms
of pale green water fleas, Daphnia
spp., and copepods, Diaptomus
spp. Occasionally, Daphnia aggregations may be so dense near shore
that in a gentle breeze they wash up on the beaches in small windrows, making
it possible to pick them up by the handful. Feeding on the zooplankton close to shore are large schools
of juvenile fishes, often numbering in the thousands. In deeper water, larger fishes of five species are also
abundant, all of them native to the lake (an unusual situation in
California). These fishes in turn
attract astonishing numbers of birds that prey upon them. Fish-eating birds such as western and
Clark's grebes, eared grebes, and osprey breed in larger numbers here than at
most places in the western United States, while other birds such as bald
eagles, American white pelicans, double-crested cormorants, Forster's terns,
California and ring-billed gulls, great blue herons, snowy egrets, and common
mergansers are common. These birds
and their constant pursuit of the fishes are one of the most conspicuous
biological features of the lake.
Their numbers are enhanced in the spring and fall when migratory
shorebirds and waterfowl use the lake by the thousands.
The
professors at then Chico State College (Drs. Vesta Holt and Thomas Rodgers) who
founded ELFS showed remarkable perception and persistence in starting a
teaching and research facility at this remote and little known lake. They began teaching classes at Eagle
Lake in 1945 but were not able to acquire the land for the present station
until 1960. They were obviously
attracted to the lake by its wild and beautiful nature, and by the abundance
and diversity of plants and animals that inhabit the lake and its basin. These same features continue to make
Eagle Lake an attractive place to teach and study natural history, particularly
because the lake is one of the least disturbed large lakes in the western
United States. This is not to say
that it is a pristine system. The
forests and rangelands of the surrounding drainage have been repeatedly logged,
burned, criss-crossed with roads, and heavily grazed. The lake level has been artificially lowered through the Bly
Tunnel project and through diversions of its principal tributary, Pine
Creek. Despite these (and other)
repeated insults to its integrity, the lake has shown remarkable resistance to
change and resilience from efforts to alter it. The keys to the maintenance of Eagle Lake's physical,
chemical, and biological integrity are (1) its water chemistry, (2) the high
percentage of public ownership of its shoreline, (3) its remoteness, and (4)
its frequent unsuitability for most conventional types of aquatic recreation.
Water
Chemistry: Eagle Lake is a terminal lake, like
many lakes in the interior of western North America. Water flows in but does not flow out, except through ground
water. As a consequence, the
minerals in the inflowing water, from precipitation, streams, and springs, are
concentrated by evaporation (106cm/year), thus making the lake highly
alkaline. Its pH is generally
around 9 and its total alkalinity is in the 400-500 range. The winds keep the shallow upper basins
well mixed most of the time, but the south basin does thermally stratify, so
the water below the thermocline can become depleted of oxygen. In winter, the lake often freezes
over. Overall, Eagle Lake is a
difficult environment for most freshwater organisms. Partly as a consequence, its biota is relatively
depauperate, consisting of species evolved to live there. The present fish fauna, for example,
consists of five species, all native.
Attempts have been made to introduce about 12 other fish species into
the lake at one time or another, but these introductions have failed. Usually, the introduced fish died
within a few hours or days, but a few (e.g. large-mouthed bass) actually
established populations for a number of years, only to succumb to the lake's
increased alkalinity in low water years.
Public
Ownership: About 80 percent of the shoreline of the
lake is publicly owned and managed, either by the BLM or the U.S. Forest
Service. Except for campgrounds
and a couple of areas leased for summer housing, this land is undeveloped. Even
much of the privately owned land around the lake has not been developed,
although it has been logged and grazed. Some of the private marshlands are
leased for hunting, so they have been maintained in reasonably good condition. The largest housing tract on the lake
is Spaulding Tract, near the mouth of Pine Creek. Spaulding is a collection of cabins and house trailers, with
a resort and airport nearby. This
little-used airport is built on the shoreline and is likely to be flooded if
the lake level continues to rise.
An
important factor in keeping the lake in good condition is the increasingly
protective attitudes of the local, state, and federal agencies that have some
responsibility for it. Lassen
County, for example, is in the process of requiring sewage treatment for the
settlements around the lake, to prevent contamination from septic tank
leachings. The California
Department of Fish and Game (DFG) is now actively managing the lake's fish
populations to maintain the high quality fishery for Eagle Lake rainbow trout,
and is opposed to attempts to introduce new species into the lake. DFG also funded (through the Wildlife
Conservation Board) the 1986 construction of a valved block in Bly Tunnel, in
order to help maintain relatively high lake levels.
Isolation: Eagle Lake is located in eastern Lassen County, one of the
most thinly populated counties in the state. The county contains vast acreage of desert, steppe,
mountain, and forest, with much of the terrain sculpted by recent volcanic
activity. Water is generally
scarce, as much of the county lies within the rain shadow of the Cascades and
Sierra Nevada. This type of
country simply cannot support large numbers of people, although it is very
attractive for summer recreation.
The lake, however, is well off the main tourist routes; it is served
mainly by narrow two-lane county highways and numerous dirt roads. Lake Tahoe, with its polluting casinos,
some two hours to the south, attracting much of the lake and mountain oriented
tourism, as does highly developed Almanor Reservoir an hour to the west. Lassen Volcanic National Park is only
an hour or so from the lake, but it is one of the least visited national parks
in the lower 48 states. The end
result is that few people have even a casual opportunity to become acquainted
with Eagle Lake and its environs, thus keeping it isolated.
Unsuitability
for Recreation: With its large and attractive setting,
Eagle Lake would seem to be an ideal place for water oriented recreation,
especially that requiring boats.
It has a major problem, however:
wind. In the summer the
wind usually starts blowing between 0930 and 1330 hrs. The wind comes up quickly; the lake can
go from a flat calm to a sea of whitecaps in less than half an hour. So serious is the problem created by
the wind that the Lassen County Sheriff maintains a large, seaworthy boat on
the lake. Its purpose is largely
to patrol the lake after the winds pick up and tow in smaller boats unable to
make it to the marinas in time.
The summer winds usually blow from the southwest, but can suddenly
switch. Once the wind starts
blowing, it generally blows strongly until after dark, and the lake usually
does not become calm until after midnight. This wind regime leaves the cool mornings as the only time
open for water skiing and power boating.
Because the water temperature is also on the cool side, it is difficult
to stay warm after getting wet.
The lake is not even particularly good for sailing, as it is either flat
calm or blowing a gale. The principal
boaters on the lake are fisherpersons who go out in the early morning after
trout. On a good weekend, there
will be several hundred fishing boats on the lake, most of them congregated in
a few 'hot spots'. As soon as the wind starts blowing, the fishing boats stream
into the marinas and the lake becomes deserted except for the pelicans and
grebes.
The
landscape around Eagle Lake is primarily volcanic in origin. Much of the lake shore is basalt
outcroppings, and Black Mountain, next to the ELFS, was an ancient
caldera. However, there are also
some granitic outcroppings on the south shore of the lake. The lake was created by a combination
of faulting and the damming of Willow creek by a lava flow. During the
Pleistocene, Eagle Lake was connected via its old outlet (about 2km north of
the ELFS) to Lake Lahontan. The
lake basin lies within the southwestern corner of the Modoc Plateau. To the immediate south of the lake, the
crest of the Sierra Nevada joins the southern end of the Cascades. Close by is Mt. Lassen Volcanic
National Park. The mountains
around Eagle Lake rise to about 2100m.
East of the lake, is the typical basin and range topography of the Great
Basin.
The
rich ecological diversity of Eagle Lake and the western fringe of the Great
Basin Desert has been of interest to Field Biologists and Ecologists for many
years. The area has also become a
major locus for research in Archaeology.
As is the case ecologically, the Eagle Lake region is
"ecotonal" for many Native American cultures including the Northern
Maidu, Northern Paiute and Pit River Indians.
Eagle
Lake, with its three basins, is a fascinating place to study limnology. Much
about the lake remains unknown, however, including the ecology and systematics
of the abundant zooplankton and benthic invertebrates including sponges,
isopods, amphipods, leeches, free-living flatworms, hydrozoans, gastropods, and
many types of insects. In the
hills around Eagle Lake are a number of ponds, mostly fishless, that contain
rich invertebrate faunas including Conchostracans, Anostracans, and
Notostracans, as well as abundant amphibian larvae. Within a half-hour to one hour drive of the station are
ponds located in Dean's Meadow, Mahogany Lake, Coleman Reservoir, as well as
three playa lakes known as the Dry Lakes, all favorites of invertebrate
biologists who come to the ELFS.
The
closest stream to the ELFS is Willow Creek, which starts in a series of springs
about 5km from the station.
Despite trampling of the riparian areas by cattle, the stream is rich in
aquatic life. There are dense beds
of macrophytes such as watermilfoil, coontail, and water cress, with large
populations of snails, dragonfly naiads, and other aquatic invertebrates. The abundant fishes find cover in these
beds and show some segregation by temperature. Rainbow trout and Paiute sculpin, for example, are found
mainly where there is cool, inflowing water. Amphibians, garter snakes (three species), and waterfowl are
also quite abundant there. Another
interesting system is Papoose Creek, near Gallatin Beach, which originates in a
couple of large springs in Papoose Meadows. Its upper reaches are full of speckled dace that chase one
another through the legs of cattle which graze in adjacent wet meadows. In summer, the lower reaches of Papoose
Creek are dry. Most distant from
the field station is Pine Creek, the principal tributary to the lake and
spawning grounds for several of the lake fishes. At its mouth, DFG operators a fish trap to capture Eagle
Lake trout, in order to collect eggs for rearing in a hatchery. There is no longer enough water in the
stream during most years for successful spawning and/or survival of the eggs
and young. The lower reaches of
the stream dry up completely, but the middle reaches are intermittent and the
upper reaches (around Bogard Campground) are a delightful cold water brook
trout stream.
Although
Dr. Robert Ediger, Professor Emeritus in the CSU, Chico Department of
Biological Sciences, has prepared a key to the plants of the Eagle Lake Basin,
new species are constantly being added to the list. A number of distinct plant communities are readily
accessible from the ELFS: (1) Sage/Juniper Steppe; (2) Montane Coniferous Forest dominated by
Jeffrey pine, incense-cedar and white fir in the transition, and red fir and
western white pine in areas above 7000ft (e.g. Antelope Mountain); (3) Basalt Ridgeline habitats dominated by
dense stands of mountain mahogany; (4) Montane chaparral dominated by shrubs such as greenleaf
manzanita and tobacco bush; (5)
Great Basin Desert habitats dominated by sage, bitterbrush, shadscale, and
black greasewood; (6) Wet
meadows of sedges, rushes and various flowering plants; (7) Riparian woodland, with alders,
cottonwoods, and willows; and (8)
Freshwater marshlands dominated by bulrush, cattails, rushes, and sedges.
For
the study of plant succession and the effects of forest fires, there are
numerous burns in the area, the closest (3km) being the Willow Creek Burn of
August 1985.
As
indicated, a large variety of aquatic and of course, terrestrial invertebrates
exist in Eagle Lake and the surrounding environs. The hatches of aquatic
insects from the lake and streams can be spectacular, quickly clogging light
traps at night. In general, the
insects and other invertebrates of the area have been little studied.
Eagle
Lake is home to five species of native fishes, all abundant. Most abundant is the tui chub, which
occurs in large pelagic schools. A
plankton and detritus feeder, it attains nearly 50cm in length. Also reaching 50cm is the Tahoe sucker,
a bottom feeder. Two small minnow
species that occur mainly in shallow water are the speckled dace and Lahontan
redside. The only piscivorous fish
in the lake is the Eagle Lake rainbow trout, a variety of rainbow trout
uniquely adapted for life in alkaline waters. Of necessity, its population and fishery is artificially
maintained by DFG. The only other
species in the drainage basin is the brook trout, found in the headwaters of
Pine Creek, which cannot survive in the lake. Willow Creek hosts essentially the same fish fauna as Eagle
Lake, with the addition of the Paiute sculpin and the exotic brown trout.
Some
five species of amphibians and 15 species of reptiles are commonly observed
within the Eagle Lake Basin. The
most common amphibian is the pacific treefrog, whose tadpoles appear in most
small bodies of water, although large bullfrogs (exotic) are becoming more and
more abundant in Willow Creek. The
amphibians are preyed upon by three species of garter snakes, which have been
intensively studied at Eagle Lake.
Western fence lizards, sagebrush lizards, and western skinks are
abundant on the rocks and within the woodland. Gopher snakes and racers are
common, and western rattlesnakes are observed occasionally as they move about
in pursuit of, among other things, the abundant rodent fauna of the region.
The
Eagle Lake region has a rich and varied bird fauna because of the wide variety
of habitats, its location on major migratory corridors, and the productivity of
the lake itself. Most conspicuous
are the water oriented birds.
Osprey are constantly visible during the spring, summer, and early fall
months, because of nests close to the station as well as the numerous nests in
the Osprey Management Area across the lake from the field station. Eared, western, and Clark's grebes form
one of the largest breeding colonies of grebes in North America, and many
western waterfowl species including Western Canada geese, gadwall, and lesser
scaup also breed in fairly large numbers. American white pelicans and
double-crested cormorants are a constant presence during the breeding season as
well. Swallows of five species
achieve high densities feeding on emerging aquatic insects. In the spring and fall, thousands of
migratory birds of all types stop over in the basin, making it a destination
for both birders and hunters.
The
mammals of the region have been poorly studied aside from a few M.S. theses of
California State University, Chico students. Over 70 species have been listed as possibly occurring in
the area, but less than half that number have been confirmed. Sightings of carnivores are relatively
uncommon, but rodents and rabbits are quite abundant at the field station and
in surrounding woodland habitats.
Common mammalian taxa frequently observed at the ELFS include mule deer,
striped and western spotted skunks, raccoon, coyote, mountain cottontail, 3
species of woodrats, 3 species of white-footed (deer) mice, the California
kangaroo rat, great basin pocket mouse, as well as several species of bats. The
western pipistrelle is the most common bat species at the ELFS, using a rocky
outcrop just to the east of the facilities as a summer roost site.
The
Eagle Lake basin is an environmentally sensitive area that would benefit from
land-use studies of many types.
Lassen County planners and administrators have been supportive of the
field station and welcome additional research efforts, especially those
centered on the lake itself.
Information that can be used in long-range planning of lakeside
developments is especially needed.
The
Eagle Lake area with it's wide diversity of habitat types is a wonderful place
to teach courses in Ecology, Field Biology and Archaeology. This region is also an excellent place
to conduct basic research in these disciplines.