Which area was settled mainly by Mormons during the mid-1800s?

There are a few settlements in Mexico and Canada and several hundred Mormon settlements throughout the Western United States. Seeing as the question is in past tense not present tense, I will answer this question based on history. In 1847 they settled in Utah near the Great Salt Lake. Mormons strongly think that the church that Jesus Christ established on the Earth in the Bible was established in the Eastern United States. 'Mormons' were in New York but were persecuted and left to Kirtland, Ohio, and Nauvoo, Illinois, then they were persecuted out of those places, and they ended up in Utah.