In Minnesota, the Minnesota Department of Health keeps statistics on hospitals and bed capacities, even subdivided by various specialties. So you could check at their website for "Health Care Providers and System Capacity": http://www.health.state.mn.us/divs/h...ers/index.html
The Minnesota Medical Association also has info online about this "Hospital Bed Capacity Task Force Report": http://www.mmaonline.net/np/hospitalexecsum.htm
Note that Minnesota Law requires the state Department of Health to approve any building of a new hospital, or expanding the bed capacity of an existing hospital. If your state does not have such legal requirements, than the state Department of Health may not have this information available.