Encounters are in /a/0/3/7 and /a/1/3/6. One's HG, one's SS. Contains:
Eight bytes for encounter rate (grass, surfing, rock smash, old rod, good rod, super rod, padding, padding)
Twelve bytes for levels
Twelve words (16-bit) for morning grass Pokémon
Twelve words for day grass Pokémon
Twelve...