Landscape Evolution at an Active Plate Margin - Biological Science ...

Nevada. Fish Slough, with 126 wetland taxa, has the
richest flora of any of the nine areas surveyed. Fish
Slough wetland flora is most similar to Fish Lake
Valley and Deep Springs Valley to the east, and least
similar to Saline Valley. Fish Slough is outstanding,
since 34 of its species do not occur at any of the nine
other wetland areas surveyed. Species with primarily
Mojavean (8 percent) and Great Basin (10 percent)
distribution are about equally represented in Fish
Slough wetlands.
Several protected plants thrive here: Fish Slough milk
vetch (Astragalus lentiginosus var. piscinensis) is a federally
listed threatened species. You cannot find this
low-growing perennial forb anywhere in the world
except the alkali meadows of Fish Slough. Nearby are
white flowers of the Inyo County star-tulip, the Alkali
mariposa lily (Calochortus excavatus; BLM Sensitive
Species). Five other rare plant species depending on
the Fish Slough are alkali cordgrass (Spartina gracilis),
hot springs fimbry (Fimbristylis), hot spring fimbristylis
(Fimbristlis thermalis), Great Basin centaury
(Zeltnera exaltata Syn: Centaurium (Centarium
exaltatum), King’s mousetailivesia (Ivesia kingii var.
kingii), and silverleaf milk vetch (Astragalus argophyllus
var. argophyllus).
Fish Slough is also critical aquatic habitat for the
Owens pupfish (Cyprinodon radiosus), Owens tui
chub (Gila bicolor snyderi), and the Fish Slough
springsnail (Pyrgulopsis pertubata). Owens pupfish
was found throughout the Owens Valley from 1859
to 1916, but water diversions and wetland drainage
by farmers caused the fish to drastically decline until
they were thought to be extinct in 1948. Two of Fish
Slough’s species, the Owens pupfish and the Owens
tui chub, are listed as endangered. In 1982, the Bureau
designated Fish Slough as an Area of Critical Environmental
Concern (ACEC) to preserve the unique
aquatic ecosystem (BLM, 2002) – but a small population
was rediscovered in Fish Slough. These pupfish
feed on insect larvae and small aquatic creatures and
can survive in warm, salty water with low oxygen
levels (see Schoenherr, this volume). The males turn
blue and silver during breeding season and vigorously
defend small territories. The Owens speckled dace is
a subspecies of speckled dace found in some places in
the Owens River. Fish and Game hopes to reintroduce
the Owens tui chub to the Slough.
RETRACE to Highway 6.
21.1 (0.4) Resume pavement.
D. R. Jessey and R. E. Reynolds
24.2 (3.1) Stop at Highway 6. TURN RIGHT (south).
25.4 (1.2) Enter Bishop.
25.7 (0.3) Stop at signal and TURN RIGHT (northwest)
on Highway 395.
27.2 (1.5) Traffic light at Barlow Road. Proceed on
Highway 395.
31.7 (4.5) Sawmill/Pleasant Valley roads junction.
Outcrops of Bishop Tuff are present on both sides of
US 395. Ahead on the skyline is the escarpment of
Wheeler Crest, composed of Wheeler Crest Granodiorite.
Proceed on Hwy 395.
34.3 (2.6) Continue past Mill Creek Road.
35.6 (1.3) Continue past Pine Creek Road. If you want
to visit the abandoned Pine Creek tungsten mine,
turn left and drive 10 miles west along Pine Creek
Canyon Road to a locked gate. The mine lies about 0.5
mile beyond the gate. The mine was closed in 1990
and more recently (2001) the existing mill was sold
and dismantled. About 600 people worked at Pine
Creek during its World War II heyday. The mine began
production of tungsten in 1918 and was acquired
by Union Carbide in 1936. Union Carbide sold the
mine and mill to Strategic Minerals Corporation in
1986. Avocet Ventures bought the mill and 50 percent
of the mine in 1995.
The mine was the largest tungsten supplier in the U.S.
Between 1937 and 1990, 83,600 tons of WO 3 (tungsten
trioxide), 12,700 tons of molybdenum byproducts,
18,300 tons of copper, 1.8 million ounces of silver,
and 3600 ounces of gold were produced (Kurtak,
1997). The ore occurs as a contact metamorphic skarn
formed when Paleozoic roof pendant rocks reacted
with hydrothermal fluids generated by intrusion of
the Sierra Nevada batholith. Continue straight on
Hwy 395 around the western edge of Round Valley.
37.2 (1.6) Begin the climb up the Sherwin Grade.
Highway 395 ascends 2500 feet over the next 10
miles. The grade is named for James Sherwin, owner
of a ranch in Round Valley. In 1874, Sherwin built a
toll road up the grade of Rock Creek to the vicinity
of present-day Toms Place. For years, U.S. Highway
395 followed the winding route of Sherwin’s toll road,
until the existing four-lane highway was built in
1956–57 across the volcanic tableland.
37.5 (0.3) Prepare to turn right; look for “Paradise/
Swale” sign.
32 2009 Desert Symposium