Alaska is around the same size as Mongolia.

Mongolia is approximately 1,564,116 sq km, while Alaska is approximately 1,481,348 sq km, making Alaska 94.71% the size of Mongolia. Meanwhile, the population of Mongolia is ~3.2 million people (2.5 million fewer people live in Alaska).
Tip: This to-scale comparison of Mongolia vs. Alaska uses the Mercator projection, which distorts the size of regions near the poles.