Walkthrough
Route 4 is found directly after Route 3; however, much like Route 2 was split in half by Viridian Forest, so Route 4 is by Mt. Moon. The western side of Route 4 is where you will enter from Route 3, being home to just one trainer and a helpful Pokemon Center.
Gift Pokemon:
Magikarp: Can Be Purchased From Man In Pokemon Center
Wild Pokemon
Sky - Special Spawns:
Dragonite: Levels 3-56
Charizard: Levels 3-56
Articuno: Levels 3-56
Zapdos: Levels 3-56
Moltres: Levels 3-56
Trainers
Coach Trainer Oberon: Level 13 Meowth
Obtainable Items
Escape Rope: Near Hiker In Pokemon Center
TM57: Defeat Coach Trainer Oberon
Post Game
Walkthrough
After defeating the Elite Four and starting the Master Trainers Challenge, you will find a couple of Master Trainers on the western portion of Route 4. In total, there are two Master Trainers for you to defeat.
Trainers
Ace Trainer Alvin (Master Trainer): Level 70 Nidoran M
Youngster Easton (Master Trainer): Level 65 Magikarp