Alaska is the U.S. state where you would find tundra and permafrost due to its polar climate.

Alaska is home to tundra and permafrost, especially in its northern and interior regions, because of its polar climate. In these areas, temperatures remain extremely cold year-round, leading to the presence of permafrost—soil that remains frozen throughout the year. The tundra biome, which is characterized by cold, windy conditions, low-growing vegetation, and minimal tree growth, thrives in this environment. Alaska's northernmost regions, such as the Arctic, have these conditions, making it one of the few places in the U.S. where tundra and permafrost are found. This climate supports unique wildlife and ecosystems adapted to the cold.