Welcome to the Lake Tahoe Data Clearinghouse website. This text-only
page is an attempt to summarize the information about Lake Tahoe and the
data available on this website. It is a condensed form of the website,
please visit the individual pages for detail and data download.
The site is designed for ease of use and navigation with the following
layout on every page:
- USGS Lake Tahoe Data Clearinghouse logo on the top.
- Menu (navigation) bar to the right.
- Signature and speed bar at the bottom.
This section is a good starting point for those interested in a variety
of information concerning Lake Tahoe.
The Lake Tahoe Data Clearinghouse website, created and maintained by
the U.S. Geological Survey (USGS) in partnership with Federal, State,
tribal, and local agencies and groups, is a gateway to information and
data on Lake Tahoe and its basin.
The primary goal of this clearinghouse is to facilitate the coordination
of research, monitoring, and environmental-management activities in
the Lake Tahoe Basin and to ensure the widest possible access to data
and information resulting from such activities. The site is designed
to ensure that all interested parties -- scientists, engineers, resource
managers, developers, and the public -- have quick and easy access to
Lake Tahoe data and information.
Users of this clearinghouse have access to a wide range of digital
data and Geographic Information System (GIS) products. Examples include
high-quality digital maps of digital elevation models, digital orthophoto
quadrangles, digital line graphs, and digital raster graphics for the
Lake Tahoe area. Some of the data resides on the USGS server at the
Western Geographic Science Center, Menlo Park, California. The majority
of the data and information, located in databases maintained by the
partnering agencies, is accessible from this clearinghouse via links.
The site is organized into 3 different sections: (1) Welcome, (2) Digital
Data, (3) General.
The USGS serves the Nation by providing reliable scientific information
- Describe and understand the Earth.
- Minimize loss of life and property from natural disasters.
- Manage water, biological, energy, and mineral resources.
- Enhance and protect our quality of life.
The mission is accomplished through data collection, research, comprehensive
studies, and information services in the broad disciplines of hydrology,
geology, biology, geography, and cartography.
The National Mapping Program of the USGS provides geographic and cartographic
data, information, and related research to meet the broad requirements
of the resource managers and Earth scientists in solving national challenges
such as disaster response and mitigation, land and resource development,
pollution abatement, transportation planning, urban development, and
On Saturday, July 26, 1997, President Clinton and Vice President Gore
traveled to Incline Village, Nevada, to host the Lake Tahoe Presidential
Recognizing the unique nature of Lake Tahoe and its surrounding basin,
the President signed an executive order in July 1997 directing Federal
agencies to establish a formal interagency partnership charged with
assuring coordination and efficient management of Federal program projects
and activities with the Lake Tahoe Basin. The Executive Order also calls
for the development of a linked natural-resources database and a Geographic
Information System (GIS) capability.
Lake Tahoe is located along the border of California and Nevada. About
one-third of the basin is in Nevada and two-thirds is in California.
The basin is bounded by the Sierra Nevada to the west and the Carson
Range to the east. The Lake Tahoe Basin was formed by geologic block
(normal) faulting about 2 to 3 million years ago. The down-dropping
of the Lake Tahoe Basin and the uplifting of the adjacent mountains
resulted in dramatic topographic relief in the region. Mountain peaks
rise to more than 10,000 ft (3,048 m) above sea level. The surface of
Lake Tahoe has an average elevation of about 6,225 ft (1,897 m).
Lake Tahoe was occupied by the Washoe Tribe for many centuries. The
Washoe Indians were hunting and fishing in the area long before General
John C. Fremont encountered it in 1844 during his exploration of the
Far West. Since then, public appreciation of Lake Tahoe has grown. Efforts
were made during the 1912, 1913, and 1918 congressional sessions to
designate the basin as a national park but were unsuccessful.
Lake Tahoe is the second deepest lake in the United States and the
tenth deepest in the world, with a maximum depth measured at 1,645 ft
(501 m), average depth of 1,000 ft (305 m). The depth of Lake Tahoe
changes every day as the lake level changes. The deepest measurement
from the 1998 bathymetric survey was 1,637 ft (499 m) deep.
Lake Tahoe is about 22 mi (57 km) long and l2 mi (31 km) wide and has
72 mi (116 km) of shoreline and a surface area of 191 mi2
(495 km2). The floor of the Lake Tahoe Basin is at an elevation
of about 4,580 ft (1,396 m). With an average surface elevation of 6,225
ft (1,897 m) above sea level, Lake Tahoe is the highest lake of its
size in the United States.
The water in Lake Tahoe could cover a flat area the size of California
14 in (36 cm) deep. This amount of water is enough to supply everyone
in the United States with 50 gallons of water per day for 5 years. The
amount of water that evaporates from the surface of Lake Tahoe every
year could supply a city the size of Los Angeles for 5 years.
The water temperature near the surface generally cools to 40 to 50oF
(4.5 to 10oC) during February and March and warms to 65 to
70oF (18 to 21oC) during August and September.
Below a depth of 600 to 700 ft (183 to 213 m), the water temperature
remains a constant 39oF (4oC).
Lake Tahoe has a water clarity of about 100 ft (30 m) deep. Factors
contributing to its clarity include the following:
- 40 percent of the precipitation that falls into the Lake Tahoe Basin
lands directly on the lake.
- Remaining precipitation drains through granitic soils, which are
relatively sterile and create a good filtering system.
This section allows users to have easy access to a wide range of digital
data and GIS products specific to Lake Tahoe. Examples include high-quality
digital maps of bathymetry, hydrography, roads, vegetation cover, forests,
timber, soils, and population for the Lake Tahoe Basin. The USGS provides
four digital cartographic products (the 4 D's):
1. Digital Elevation Model (DEM).
2. Digital Orthophoto Quadrangle (DOQ).
3. Digital Line Graph (DLG).
4. Digital Raster Graphic (DRG).
GIS data depot for all available data downloads and metadata are linked
from here. Downloadable data are available for the following topics:
DEM, DOQ, DLG, DRG, Bathymetry, Landsat, Landcover, Census, and Soils.
The Lake Tahoe Basin covers 18 7.5-minute quadrangle maps. These 18
individual quads have been mosaicked together. The mosaicked files are
more convenient for looking at areas throughout the basin or areas on
the edge of two quadrangles. Data are in UTM NAD27 zone 10 projection.
Raw (original) data are in the following projections: data east of
120 degrees longitude are in UTM zone 11 and data west of 120 degrees
longitude are in UTM zone 10. It is not possible to combine different
projections in Geographic Information System (GIS), therefore, all data
have been reprojected into one standard projection, UTM NAD27 zone 10
projection, for the Lake Tahoe Basin.
Here is an index of the individual quads that cover the Lake Tahoe
Cartographic/geographic data of elevations in xyz coordinates (view
data in 3-dimensions).
A Digital Elevation Model (DEM) is digital cartographic/geographic
data in raster form. The terrain elevations for ground positions are
sampled at regularly spaced horizontal intervals. DEMs are derived from
hypsographic data (contour lines) and/or photogrammetric methods using
USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute), and 1-degree
(1:250,000-scale) topographic quadrangle maps.
Data Downloads are available for 10-meter resolution, with or without
the bathymetry data. Formats are available for ArcInfo export and JPEG
with world file.
Digital, uniform-scale image created from aerial photos (a photographic
A Digital Orthophoto Quadrangle (DOQ) is a digital, uniform-scale image
created from aerial photos. It is a photographic map in which ground
features are displayed in their true ground position, because relief
displacements caused by the camera and terrain of an aerial photograph
have been removed. It combines the image characteristics of a photograph
with the geometric qualities of a map, thus it is possible to get direct
measurements of distances, areas, angles, and positions from a DOQ.
Data Downloads are available in MrSID format with world file for year
1992 and 1998.
Cartographic data in vector format (geographic data in points, lines,
A Digital Line Graph (DLG) is digital vector data representing cartographic
information. DLGs contain a wide variety of information depicting geographic
features (for example, hypsography, hydrography, boundaries, roads,
utility lines, etc). DLGs are derived from hypsographic data (contour
lines) using USGS 7.5-minute, 15-minute, 2-arc-second (30- by 60-minute),
and 1:2 million-scale topographic quadrangle maps.
Data Downloads are available in Spatial Data Transfer Standard (SDTS),
ARC/INFO export, and shapefile format for the following items: Hypsography,
Hydrography, Vegetation, Roads, and Human-made features
A scanned version of the USGS 7.5-minute topographic map.
A Digital Raster Graphic (DRG) is a digital image (scanned version)
of the USGS topographic map. DRGs are produced from USGS 1:24,000-,
1:24,000/1:25,000-, 1:63,360- (Alaska), 1:100,000-, and 1:250,000-scale
topographic map series. The image inside the map neatline is georeferenced
to the surface of the Earth and fit to the Universal Transverse Mercator
(UTM) projection. The horizontal positional accuracy and datum of the
DRG matches the accuracy and datum of the source map.
Data Downloads are available in GeoTIFF and MrSID formats with world
Relief map and data of the lake floor of Lake Tahoe.
The Lake Tahoe Bathymetry survey was conducted on August 1998 using
the latest-generation multibeam system by the USGS Western Region Coastal
and Marine Geology Branch in cooperation with the Ocean Mapping Group
(OMG) of the University of New Brunswick, Canada. The multibeam mapping
system records both the bathymetric data (depth information) and the
backscatter data (the strength of sound energy that bounces back). This
information can help scientists identify the materials that make up
the lake floor, such as rock, sand, or mud. New data can shed light
on the history hidden by the waters of Lake Tahoe.
Data Downloads are available for the following items: High-resolution
images from the bathymetric survey, Fly-by Movie, different types of
bathymetry DEM files in ARC/INFO format.
Satellite image of Earth's surface.
The USGS Landsat 7 satellite provides medium-resolution image information
of the Earth's surface. It is a multispectral scanner that collects
visible, near-infrared, short-wave, and thermal infrared frequency bands
from the sun-lit Earth. Nominal ground sample distances or "pixel" sizes
are 49 ft (15 m) in the panchromatic band; 98 ft (30 m) in the 6 visible,
near and short-wave infrared bands; and 197 ft (60 m) in the thermal
Data Downloads are available in GeoTIFF and IMAGINE format.
Information of Earth's surface.
Data Downloads are available in GeoTIFF and ARC/INFO Grid format
Data Downloads are available in Spatial Data Transfer Standard (SDTS),
ARC/INFO export, and shapefile formats.
A survey of the soil types in Lake Tahoe region.
Data Downloads are available for the SSURGO data in Spatial Data Transfer
Standard (SDTS), ARC/INFO export, and shapefile formats.
This section consists of general interest information.
Lake Tahoe Data Clearinghouse (LTDC) is a success because of the support
and contributions of data and information from many different organizations
working together. The Tahoe Federal Interagency Partnership brings together
Federal, tribal, State and local agencies along with local groups and
individuals that share a common goal of helping everyone enjoy the natural
beauty of the area.
Here is a partial list of the groups involved with the Partnership:
- U.S. Department of Interior (DOI)
- U.S. Geological Survey (USGS)
- U.S. Forest Service (Lake Tahoe Basin Mangement Unit) (USFS)
- Natural Resources Conservation Service (NRCS)
- Tahoe Regional Planning Agency (TRPA)
- U.S. Department of Agriculture (USDA)
- U.S. Department of Transportation (DOT)
- U.S. Environmental Protection Agency (EPA)
- U.S. Postal Service (USPS)
- U.S. Army Corps of Engineers (USACE)
- State of California
- State of Nevada
- Washoe Tribe of Nevada and California
- University of California - Davis (UCDavis)
- University of Nevada, Reno
- Desert Research Institute (DRI)
Questions and Answers regarding the Lake Tahoe Data Clearinghouse.
Listed are the questions asked. Please visit the Help Desk page for
- Who maintains this website?
- Can I link to this website?
- How can I view the data?
- Where do the data come from?
- What is a projection?
- The data are in what projection?
- How do I change projections?
- How can I view the DEM elevation information in Arcview?
- Is there similar data on other areas?
- How do I view data in MrSID format?
- Can I see objects on the bottom of Lake Tahoe?
- Is there a poster version of the bathymetry available?
This page contains miscellaneous maps from a variety of sources available
across the internet. These maps are images rather than GIS ready data.
Maps available for road, quads locator, satellite, national map, slope,
and bathymetry with steam monitoring sites.
Views of Lake Tahoe from Earth and Space.
The beauty of nature becomes more and more precious to us as civilization
continues to grow. The experience we gain from exploring nature imprints
a special memory within our heart. The experience is refreshing as we
allow the serenity to regenerate our mind and soul. Nature allows us
to expand our knowledge toward understanding the foundation of life,
and directs our focus toward finding appreciation and happiness in life's
Lake Tahoe is one of mother nature's most beautiful creations. From
its alpine mountains to its flowing streams, Lake Tahoe is the place
where we go to revive our mind and body. Its tranquil beauty refreshes
and soothes us as we breathe in its refreshing scent. The awe-inspiring
landscape opens our mind to a new perspective of life.
Although pictures cannot replace the experience of reality, it is a
good place to start.
A list of sources and references to Lake Tahoe reports and links.
News and Reports -- News, reports, and research papers about Lake Tahoe.
Notes and Minutes -- Basin Watch, Lake Tahoe Interagency Monitoring
Program (LTIMP), Upper Truckee River Focused Watershed Group (UTRFWG),
Water Quality Working Group (WQWG).
Other Links -- Can't find what you need here? Try some other links
about Lake Tahoe.
All information provided is deemed reliable but is not guaranteed and
should be independently verified.
Highlighted and (or) underlined terms are clickable and will take you
to a new page. The footer symbol ()
marks links to external web sites and selected pages that will open in
a new window, with a few exceptions. Exceptions include but are not limited
to the following: no footer symbol ()
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