Topography and Our Natural Heritage

Yosemite National Park (USA) is in California’s Sierra Nevada mountains. It’s famed for its giant, ancient sequoia trees, and for Tunnel View, the iconic vista of towering Bridalveil Fall and the granite cliffs of El Capitan and Half Dome. The interactive topographic map above covers much of Yosemite National Park. Use the map above to help answer the questions below.

The interactive map above is primarily a topographic map. Thin brown topographic contour lines cover the map and indicate elevation. Contour lines are lines of equal elevation, so elevation would be constant if you hiked along the contour line. They are useful because the lines show the form of the land surface on the map–its topography. Topographic maps show lines for certain elevations only. These lines are evenly spaced apart. This spacing is the contour interval. Different maps use different intervals. Ten feet is a common contour interval used in U.S. topographic maps.

Surface water is a key geographic feature of topographic maps. Nearly always blue, water can be represent streams and river with lines or lakes and oceans with polygons.

As you can tell from the topmost interactive map, Yosemite has a wide range of amazing natural features - but at least in the topographic map above - one stands out.

Contour index lines have intervals that indicate absolute elevation. They also tell us how many vertical feet are between each normal contour line. This contour interval can be different for each map. Find two index contours and calculate the vertical change between each normal contour line.

People from around the world visit Yosemite to climb Half Dome. It is a granite dome at the eastern end of Yosemite Valley, named for its distinct shape. One side is a sheer face while the other three sides are smooth and round, making it appear like a dome cut in half. The granite crest rises more than 4,737 ft (1,444 m) above the valley floor. (Wikipedia)

Use the interactive map above to locate Half Dome.

Learn more about Yosemite National Park at the  National Park Service website. >>