UNITED STATES

UNITED STATES.

National Parks.
Yellowstone Old Faithful geyser in eruption.
First stamp in a set of 3, issued on 30.07.1934.
Face value: 5 cents.
Printing: Recess.
Print: 30,000,000 copies.
Size: 27 x 40 mm.

Catalogues
- Michel No. 368.
- Scott No. 744.
- StampWorld No. 585.
- Stanley Gibbons No. 743.
- Yvert et Tellier No. 332.

Yellowstone National Park, with an area of 3468.4 sq mi (8,983.2 km²), occupies territories of the states of Idaho, Montana and Wyoming. It was the first national park to be established in the United States, in 1872. The relief of the park includes lakes, canyons, rivers and mountain ranges, and also the Yellowstone caldera, the largest supervolcano in the American continent, currently inactive, but has erupted several times in the last two million years. Thanks to its continuous volcanic activity, Yellowstone is also home to half of the world's geysers and hydrothermal vents. Old Faithful geyser, located in Teton County (Wyoming), received this name in 1870. The eruptions, which last from one and a half to five minutes, can release between 3,700 and 8,400 US gallons (14,000 to 32,000 L) of water boiling at a height of 106 to 185 ft (32 to 56 m). The intervals between eruptions can vary from 60 to 110 minutes.