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.
Appointment may refer to: The prerogative power of a government official or executive to select persons to fill an honorary position or employment in the government (i.e. political appointments, poets laureate). Power of appointment, the legal ability of a testator to select another person to dispose of the testator's property.