Riverside County and San Bernardino County to the north form this metro area. Like many such metro areas in the Southwest, it extends far into uninhabited desert areas, in this case east through the Mojave Desert to the Nevada/Arizona border. Larger than nine U.S. states, it is often referred to as the Inland Empire.
I agree with tchrist that the word doctor in doctor appointment is a noun (attributive noun I believe), although the definition of an attributive noun is a noun used as an adjective, so maybe it's just semantics at some point.
Note that in many systems outpatient encounters (which are in scope for Encounter) and Appointment are used concurrently. In FHIR, Appointment is used for establishing a date for the encounter, while Encounter is applicable to information about the actual Encounter, i.e., the patient showing up.