Part 4: Beat Whitney — Goldenrod City Gym, badge 3

Beat Whitney — Goldenrod City Gym, badge 3 opens 17 areas. There are 103 trainers standing in them. The fights at this checkpoint are Rival Silver (Chikorita), Rival Silver (Cyndaquil), Rival Silver (Totodile), and 1 more.

Where to go

1. Mt. Mortar

   Wild: Goldeen 90% · Lv 15-24, Magikarp 85% · Lv 10, Zubat 60% · Lv 13-15, Geodude 50% · Lv 13-15 +9 more

   Trainers: Blackbelt Kiyo Lv 34

   Pick up: TM40 Defense Curl

2. Route 37

   Wild: Caterpie 65% · Lv 10, Weedle 65% · Lv 10, Hoothoot 60% · Lv 13-15, Pidgey 60% · Lv 13-15 +12 more

   Trainers: Psychic Greg Lv 17, Twins Ann & Anne Lv 16, Twins Ann & Anne Lv 16

3. Route 38

   Wild: Caterpie 65% · Lv 10, Weedle 65% · Lv 10, Rattata 40% · Lv 16, Meowth 30% · Lv 16 +12 more

   Trainers: Beauty Valerie Lv 17, Bird Keeper Toby Lv 17, Lass Dana Lv 18, Lass Dana Lv 21, Lass Dana Lv 29, Sailor Harry Lv 19 +3 more

4. Route 39

   Wild: Caterpie 65% · Lv 10, Weedle 65% · Lv 10, Rattata 40% · Lv 16, Meowth 30% · Lv 16 +11 more

   Trainers: Pokéfan Derek Lv 17, Pokéfan Derek Lv 19, Pokéfan Derek Lv 36, Pokéfan Ruth Lv 17, Psychic Norman Lv 20, Sailor Eugene Lv 19

5. Route 42

   Wild: Goldeen 90% · Lv 15-24, Magikarp 85% · Lv 10, Spearow 80% · Lv 10, Mareep 50% · Lv 13-15 +6 more

   Trainers: Fisher Chris Lv 18, Fisher Chris Lv 23, Fisher Chris Lv 34, Hiker Benjamin Lv 16, Pokémaniac Shane Lv 16

6. Route 43

   Wild: Magikarp 100% · Lv 10-24, Poliwag 80% · Lv 40, Spearow 80% · Lv 10, Flaaffy 40% · Lv 15-17 +7 more

   Trainers: Camper Spencer Lv 19, Fisher Marvin Lv 15, Picnicker Tiffany Lv 31, Picnicker Tiffany Lv 37, Picnicker Tiffany Lv 20, Pokémaniac Ben Lv 19 +4 more

   Pick up: TM36 Sludge Bomb

7. Route 44

   Wild: Remoraid 100% · Lv 10, Poliwag 90% · Lv 20-29, Magikarp 85% · Lv 10, Spearow 80% · Lv 10 +7 more

   Trainers: Bird Keeper Vance Lv 25, Bird Keeper Vance Lv 33, Bird Keeper Vance Lv 37, Cooltrainer Allen Lv 27, Cooltrainer Cybil Lv 25, Fisher Edgar Lv 25 +5 more

8. Route 45

   Wild: Magikarp 100% · Lv 5-24, Spearow 80% · Lv 10, Graveler 55% · Lv 23-25, Dratini 30% · Lv 40 +8 more

   Trainers: Blackbelt Kenji Lv 32, Blackbelt Kenji Lv 37, Blackbelt Kenji Lv 28, Cooltrainer Kelly Lv 27, Cooltrainer Ryan Lv 27, Hiker Erik Lv 27 +5 more

9. Burned Tower

   Wild: Koffing 50% · Lv 14-16, Rattata 50% · Lv 13-15, Magmar 15% · Lv 14-16, Zubat 10% · Lv 14 +1 more

   Trainers: ★ Rival Silver (Chikorita) Lv 22, ★ Rival Silver (Cyndaquil) Lv 22, ★ Rival Silver (Totodile) Lv 22, Firebreather Dick Lv 17, Firebreather Ned Lv 16

   Pick up: TM20 Endure

10. Blackthorn City

    Wild: Magikarp 100% · Lv 5-19, Poliwag 80% · Lv 40, Rhydon Lv 30-100

    Pick up: TM24 Dragon Breath

11. Lake of Rage

    Wild: Magikarp 100% · Lv 10, Caterpie 65% · Lv 10, Weedle 65% · Lv 10, Gyarados 30% · Lv 40 +6 more

    Trainers: Cooltrainer Aaron Lv 24, Cooltrainer Lois Lv 25, Fisher Andre Lv 27, Fisher Raymond Lv 22

    Pick up: TM10 Hidden Power, TM43 Detect

12. Olivine City

    Wild: Tentacool 90% · Lv 15-24, Magikarp 85% · Lv 10, Krabby 60% · Lv 40, Corsola 30% · Lv 40 +4 more

    Pick up: TM23 Iron Tail, HM04 Strength

13. Ecruteak City

    Wild: Poliwag 90% · Lv 15-24, Magikarp 85% · Lv 10, Poliwhirl 10% · Lv 20-24

    Trainers: Kimono Girl Kuni Lv 17, Kimono Girl Miki Lv 17, Kimono Girl Naoko Lv 17, Kimono Girl Sayo Lv 17, Kimono Girl Zuki Lv 17

    Pick up: TM30 Shadow Ball, HM03 Surf

14. Lighthouse

    Trainers: Bird Keeper Denis Lv 20, Bird Keeper Theo Lv 19, Gentleman Alfred Lv 20, Gentleman Preston Lv 18, Lass Connie Lv 21, Sailor Ernest Lv 18 +5 more

15. Mahogany Town

    Trainers: Rocket Executive Lv 24, Rocket Executive Lv 25, Rocket Grunt Lv 16, Rocket Grunt Lv 18, Rocket Grunt Lv 17, Rocket Grunt Lv 18 +7 more

16. Route 40

    Trainers: Swimmer♀ Elaine Lv 21, Swimmer♀ Paula Lv 19, Swimmer♂ Randall Lv 20, Swimmer♂ Simon Lv 20

17. Goldenrod City Gym

    Trainers: ★ Whitney Lv 20, Beauty Samantha Lv 16, Beauty Victoria Lv 17, Lass Bridget Lv 15, Lass Carrie Lv 18

★ Rival Silver (Chikorita) — Burned Tower

4 Pokémon · level cap Lv 22 (every cap) · Rival Silver (Chikorita)’s own page

	Pokémon	Moves
	Haunter Lv 20	Lick Spite Mean Look Curse
	Magnemite Lv 18	Tackle Thunder Shock Supersonic Sonic Boom
	Zubat Lv 20	Leech Life Supersonic Bite Confuse Ray
	Bayleef Lv 22	Growl Reflect Razor Leaf Poison Powder

★ Rival Silver (Cyndaquil) — Burned Tower

4 Pokémon · level cap Lv 22 (every cap) · Rival Silver (Cyndaquil)’s own page

	Pokémon	Moves
	Haunter Lv 20	Lick Spite Mean Look Curse
	Magnemite Lv 18	Tackle Thunder Shock Supersonic Sonic Boom
	Zubat Lv 20	Leech Life Supersonic Bite Confuse Ray
	Quilava Lv 22	Leer Smokescreen Ember Quick Attack

★ Rival Silver (Totodile) — Burned Tower

4 Pokémon · level cap Lv 22 (every cap) · Rival Silver (Totodile)’s own page

	Pokémon	Moves
	Haunter Lv 20	Lick Spite Mean Look Curse
	Magnemite Lv 18	Tackle Thunder Shock Supersonic Sonic Boom
	Zubat Lv 20	Leech Life Supersonic Bite Confuse Ray
	Croconaw Lv 22	Leer Rage Water Gun Bite

Also fought around here

Everything you can have caught by this checkpoint · Open the interactive guide

It also doesn't say when 5 of its areas open up, so they are listed together in the last part rather than guessed into the story.