It doesn't show larger hospitals, so it is hard to directly answer the question about access to emergency care, but it shows that there is quite wide geographic coverage. The map in this article shows that the gaps are just where you would expect, in the extraordinarily rural west:
The closest hospital from me is an hour away. 45 if you drive semi-fast. That time + whatever response time is. We had to call an ambulance for my father once and it was 20-30 minutes for them to arrive. It's not really that uncommon.
There’s a meaningful difference between “it was 20-30m for them to arrive” and the previous post’s “hours.” Almost an order of magnitude’s difference.
And that’s a medically meaningful difference. 20m response time, 45m to the hospital, you’re still in the time window for critical therapies for heart attacks and strokes. Several hours response time, you’re not. I mean to say, I’m not nitpicking: the difference between your scenario and what the previous poster asserts is large and medically meaningful.
When I was growing up in the rural Midwest, about 30 minutes from the nearest small-town hospital, we waited nearly an hour and a half for an ambulance to arrive to help my sister with an asthma attack because my mom couldn't drive and keep her breathing at the same time.
Where? I live in an very remote part of Northern Minnesota. Even so, worst case ambulance time to most people in my area would be 15-20 mins.
I would argue that an incredibly small portion of the US population lives >1hr from an ambulance or first responder.