Montana is about 2.1 times smaller than Turkey.

Turkey is approximately 783,562 sq km, while Montana is approximately 376,979 sq km, making Montana 48.11% the size of Turkey. Meanwhile, the population of Turkey is ~83.0 million people (82.1 million fewer people live in Montana).
Tip: This to-scale comparison of Turkey vs. Montana uses the Mercator projection, which distorts the size of regions near the poles.