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.
1.5 'Appointment' means an offer by an appointing authority to a qualified person of employment in a classified position and the acceptance of such offer. 1.5.01 'Article' or 'Civil Service Article' means Article X, Part I of the Constitution of the State of Louisiana of 1974, ratified by the electorate of Louisiana. 1.5.01.1 'Base Pay' means the employee's hourly rate (including rate within base supplement) and any supplemental pay authorized by the Article.