Are the entrances to the rooms in an interior hallway or are the doors open to the outside?

Depends on which building you are in. The building with the lobby has interior openings. The other building (across an alley) has exterior doors and no elevator.

Interior

Interior entrance

Cathryn is the only one you should listen to. The building across the alley is exterior entrances only (at least for the rooms I saw)

All from inside,front anf back entrances

Interior hallway.

Interior, nice hotel close to the Grand canyon.