Route 37

11 species to catch in 1 area of this location, across 5 game versions.

Data from Pokemon HeartGold only: exact levels and the encounter rate for each Pokémon.

in tall grass

Conditional slots 13 for 9 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Pidgey	in the morning	13–15	24%
	during the day	13	20%
	radio off, in the morning	13–15	20%
	radio off, during the day	13–15	20%
Pidgeotto	during the day	15	4%
Growlithe	during the day	15	4%
Hoothoot	radio off, at night	15	10%
Spinarak	at night	13–15	24%
	radio off, at night	13	10%
Stantler	radio off	15	10%
Plusle	radio on Hoenn Sound	13–15	20%
Minun	radio on Hoenn Sound	15	10%
Shinx	radio on Sinnoh Sound	13–15	20%

by headbutting trees (Headbutt)

Conditional slots 6 for 4 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Exeggcute	common tree	12–14	10%
	rare tree	15–17	10%
Hoothoot	common tree	12–14	50%
	rare tree	15–17	50%
Spinarak	rare tree	15–17	15%
Pineco	common tree	12–14	15%

The red marker is Route 37. A diagram, not a world map — distances are not to scale, but directions and connections match the game. The legend below the drawing explains each symbol.

• Route — number inside
• Sea route — Surf only
• City
• Interior — cave, forest, tower; placed next to its entrance
• Path between places
• Path that requires Surf
• Entrance to an interior — not a passage to the other side

Directions read from the map layout in the games — from how the screens connect to each other. We know them for Kanto, Johto, Hoenn and Sinnoh; in other regions you will not see this section, because we have no source for the topology.