Pokéarth - Johto - Route 46

Walkthrough:Pokémon HeartGold and SoulSilver, Pokémon Wiki

Pokémon HeartGold and SoulSilver/Route 31 — StrategyWiki

Route 29 Johto, Pokémon Heartgold & Soulsilver

Johto Route 40 - Bulbapedia, the community-driven Pokémon encyclopedia

Pokéarth - Johto - Route 34

Pokemon Heart Gold Kanto 06: Route 25!

Ryan Polito - My Kanto Re-Creation Project

Pokémon HeartGold and SoulSilver/Johto — StrategyWiki

Heart Gold and Soul Silver: (hidden) items, TMs, HMs and other (nuzlock) stuff - heartgold post - Imgur

Here is a map I made with the location and info for all catchable