Answers. Best Answer: Six The major land biomes of the United States are tundras, coniferous forests, deciduous forests, tropical rain forests, grasslands, and deserts. Tundra biomes cover about 10 percent of the Earth's surface. In the United States, tundra biomes are found only in parts of Alaska. The climate of a tundra is extremely cold and dry. In fact, you could think of a tundra as a cold desert. Less than 25 centimeters of rain and snow fall on a tundra during most years.