Pinto
Valley as
seen from Hamblin Peak (view east)
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Overview
Pinto Valley is a large (39,173 acres) wilderness
area
located
on the north edge of Lake Mead. This is a wild and geologically complex
country composed of volcanic, carbonate, sandstone, and sedimentary
rocks, all stirred together by major fault systems and cut by major
drainages. In the southern part of the wilderness area, the volcanic
Black
Mountains (several peaks around 3,300 feet) border Lake Mead. In the
northern part, the mountains are titled carbonate ridges (peaks to
about 3,000 feet) with sandstone outcrops. Between the two, gypsum mud
hills provide evidence of ancient lakes and now provide habitat for
rare plants. The vegetation generally is sparse Mojave Desert
Scrub,
dominated by creosote
bush and white
bursage, but with a diverse flora
of annual and perennial plants. Washes support catclaw
acacia, honey
mesquite, and other shrubs, and the springs provide water for
cottonwood
trees, bighorn
sheep, and other wildlife.
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Cottonwood Spring (view south). |
This wilderness area is separated from the
Jimbilnan
Wilderness Area
by a one-lane dirt road, but combined they protect some 58,000 acres of
designated wilderness. In addition, these two areas are almost
connected with the Muddy Mountains Wilderness Area, which if included
in the total, covers about 106,100 acres.
If you hike in wilderness areas, help protect them by learning about and reporting noxious and invasive weeds.
Link to map
of the wilderness
area.
Link to hikes
in the wilderness area.
Location
The Pinto Valley
Wilderness Area is located about 30 air-miles east of Las Vegas,
entirely within Lake Mead National Recreation Area. The wilderness area
lies between Northshore Scenic Drive and Lake Mead.
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Boathouse Cove Road (view west). |
Boundaries
The northern boundary is Lakeshore Scenic Drive,
extending
from Callville Wash Road on the west to Boathouse Cove Road on the
east. The eastern boundary is Boathouse Cove Road, which also borders
the Jimbilnan Wilderness Area. The southern boundary is Lake Mead,
extending from the Virgin Basin to the Boulder Basin. The western
boundary is Callville Wash Road.
Access
Access to the wilderness area is from the paved
Northshore Scenic
Drive and from the rough dirt roads that border the west (Callville
Wash Road) and east (Boathouse Cove Road) sides of the wilderness area.
The wilderness area can also be accessed from Lake Mead by boat.
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Flats, hills, and rugged peaks (view west from near Boathouse Cove). |
Terrain
The terrain is
rugged. The Black Mountains, essentially everything east, south, and
west of Pinto Valley, proper, are volcanic. The mountain peaks
generally are low (elevations only to about 3,300 feet), but what they
lack in height, they make up for in ruggedness. North of Pinto Valley,
proper, the landscape is titled carbonate ridges. Faults align a series
of three major ridges (Northshore Peak, Razorback Ridge, and Pinto
Ridge), where elevations reach about 3,000 feet. Included in the jumble
of terrain are gypsum mudhills and red sandstone outcrops.
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Silver-leaf
Sunray in the gypsum mud hills.
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Habitat
Type
The Pinto Valley Wilderness Area is located
entirely
within
the Upper Sonoran (Mojave
Desert Scrub) life zone, and the vegetation
is primarily composed of typical Mojave Desert species. The
valleys and bajadas are dominated by species such as creosote
bush, white
bursage, Fremont's
dalea (Indigo Bush), and Mojave yucca.
A
wide variety of less common plants also occur in these areas. A number
of cactus species occur in the area, including beavertail
pricklypear cactus, silver
cholla, cottontop
cactus, and common
fishhook cactus. Even California
barrel cactus, usually found on
rocky hillsides, can be found on the bajadas. Joshua trees,
typical of many parts of the Mojave Desert, seem to be
absent.
The mountain slopes support species such
as creosote
bush, white
bursage, Nevada
jointfir, Schott's
pygmycedar, sweetbush,
and goldenhills
(Brittlebush). Washes support a diverse array of shrubs,
including catclaw
acacia, burrobrush,
and babbitbrush.
The gypsum mudhills support and odd array of rare
species, including silverleaf
sunray, California
(Las Vegas) bearpoppy, and Palmer's
phacelia.
Cryptobiotic crusts, and even moss, grow on the seemingly inhospitable
gypsum mudhills.
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Sandstone Spring (view south). |
Sandstone Spring, once developed to provide
water for cattle, now supports honey
mesquite, catclaw
acacia, desert
almond, four-wing
saltbush, saltgrass,
and other shrubs. The watering
trough and pipes are still there, but they are nonfunctional. Bighorn
sheep, coyote, and small mammals also use the spring.
Cottonwood
Spring provides water for two cottonwood
trees, a thicket of honey
mesquite, and catclaw
acacia. Wild burros are making a mess here.
Invasive species such as saltcedar
and russian
thistle occur in some washes.
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Lake Mead as seen from Northshore
Peak (view west).
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Wildlife
Bighorn
sheep, coyote, and Black-tailed
Jackrabbit are common
in the wilderness area. Unfortunately, wild burros seem to have invaded the area
around Cottonwood Spring. Bird species in the desert portions of the
wilderness area include Cactus Wren, Say's Phoebe, Common
Raven, Sage
Sparrow, House Finch, Black-tailed Gnatcatcher, Loggerhead Shrike,
Yellow-rumped Warbler, and Bald Eagle. Along the lake, common
"waterbirds" include American coots, grebes,
mergansers, and gulls.
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Archaeology
No specific information on prehistoric use in the
wilderness area, but native
peoples provided evidence of their presence by
leaving petroglyphs. Native peoples often marked on rocks faces that
are readily seen from easy walking routes (such as washes) and that
often
seem to serve sign-posts. Here, however, they marked on
out-of-the-way spots such as the top, but not the sides, of boulders.
There is also evidence of early survey efforts and
early
white
travelers in the area. In the only shady place in western Pinto Valley,
there are the remains of what appears to be an old cowboy camp (rock
shelter, old boards, rusty cans, and rock carvings).
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Rock layers along edge of wash.
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Geology
The Black Mountains are
Tertiary volcanics, and Pinto Valley and points north are older
carbonate rocks with a bit of red Jurassic sandstone mixed in. The area
is affected by the Las Vegas Valley Shear Zone, the Bitter Springs
Valley Fault, and the Hamblin Bay Fault. These faults have left their
mark by doing things like splitting mountains and tilted others on
edge. Boulder Wash drains the area through a fault-induced canyon that
cuts through the Black Mountains to Lake Mead.
The Hamblin-Cleopatra
Volcano story is particularly impressive. Some 13 million years ago,
the Hamblin-Cleopatra Volcano was split by the Hamblin Bay Fault, which
runs east-west. In the following 3 to 8 million years, the Cleopatra
lobe (the southern half of the volcano) shifted to the east, while
Hamblin Mountain (the northern half) shifted to the west. Hamblin
Mountain is now about 12 miles west of the Cleopatra lobe -- that's a
spread of nearly 2 miles per million years or faster! The Cleopatra
lobe is now over in the Jimbilnan Wilderness Area. The Nevada Bureau of
Mines and Geology publishes a nice book, "Geologic Tours in the Las
Vegas Area, Expanded Edition" [ISBN 1-888035-07-2; about $20] that
details the story in a format that is interesting and readable for lay
people.
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Colorful layers on the north side of Pinto Valley (view north).
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Threats
Off-road vehicles are somewhat of a threat from
the
roads that
border the wilderness area. There is no evidence of pervasive problems
from Boathouse Cove Road, as people seem to be respecting signs and
barricades blocking old roads into the wilderness area. Boathouse Cove
is somewhat trashed, but cliffs contain the damage and trash to the
camping area. Motorcycles have penetrated some of the canyons off
Northshore Road, but the problem does not seem to be pervasive.
Invasive species such as saltcedar and Russian
thistle occur
in some washes and along the lakeshore. Wild burros seem to have
recently invaded the Cottonwood Spring area and are making quite a mess.
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