Denver and SLC are reasonably big cities. If you need, for example, a big-city childrens' hospital, they have them.
Then you start to drive out of town, and there is N O T H I N G. I mean, from SLC, there's Ogden and Provo, maybe Park City. From Denver, there's Colorado Springs and Fort Collins. Once you get past those, it's a long way to the next anywhere.
So are they isolated? Depends on how you define isolation. Does that particular kind of isolation affect depression and/or suicide? No clue.
Then it would be interesting to compare those cities to my own. If you leave the metro area, there is basically nothing in any direction for many hundreds of miles. But our elevation is at sea level instead of elevated.
I live in that "long way to anywhere" zone (a day's drive from both Salt Lake and Denver). Lots of suicide here (annual 41 deaths by suicide per 100,000 people).
Then you start to drive out of town, and there is N O T H I N G. I mean, from SLC, there's Ogden and Provo, maybe Park City. From Denver, there's Colorado Springs and Fort Collins. Once you get past those, it's a long way to the next anywhere.
So are they isolated? Depends on how you define isolation. Does that particular kind of isolation affect depression and/or suicide? No clue.