United States
vast central plain, mountains in west, hills and low
mountains in east; rugged mountains and broad river valleys in
Alaska; rugged, volcanic topography in Hawaii

United States Pacific Island Wildlife Refuges
low and nearly level
sandy coral islands with narrow fringing reefs that have developed
at the top of submerged volcanic mountains, which in most cases rise
steeply from the ocean floor

Uruguay
mostly rolling plains and low hills; fertile coastal lowland

Uzbekistan
mostly flat-to-rolling sandy desert with dunes; broad,
flat intensely irrigated river valleys along course of Amu Darya,
Syr Darya (Sirdaryo), and Zarafshon; Fergana Valley in east
surrounded by mountainous Tajikistan and Kyrgyzstan; shrinking Aral
Sea in west

Vanuatu
mostly mountainous islands of volcanic origin; narrow
coastal plains

Venezuela
Andes Mountains and Maracaibo Lowlands in northwest;
central plains (llanos); Guiana Highlands in southeast

Vietnam
low, flat delta in south and north; central highlands;
hilly, mountainous in far north and northwest

Virgin Islands
mostly hilly to rugged and mountainous with little
level land

Wake Island
atoll of three low coral islands, Peale, Wake, and
Wilkes, built up on an underwater volcano; central lagoon is former
crater, islands are part of the rim

Wallis and Futuna
volcanic origin; low hills