The Safari Zone Gets an Upgrade After you defeat the Elite 4. 2 More Areas to the right of the entrance are opened up.

These 2 Areas Contain a vast array of GSC Pokémon...and to make it even tastier, most of these have been unavailable in games previously without having to breed Colosseum Pokémon
You're Going to need the following things to get the best use out of these areas: HM06 Rock Smash, HM07 Waterfall, HM03 Surf & A Super Rod

Here are the Pokémon you will find in the wild in Safari Zone's New Areas:

In The Area 1's Grass
	Sunkern	Common
	Mareep	Common
	Aipom	Uncommon
	Spinarak	Uncommon
	Hoothoot	Uncommon
	Snubbull	Uncommon
	Stantler	Rare
	Gligar	Rare
In The Area 2's Grass
	Aipom	Common
	Teddiursa	Common
	Sunkern	Uncommon
	Ledyba	Uncommon
	Hoothoot	Uncommon
	Pineco	Uncommon
	Houndour	Rare
	Miltank	Rare
In The Area 1's Waters (Surf)
	Wooper	Common
	Marill	Common
	Quagsire	Rare
In The Area 1's Waters (Fish)
	Remoraid (Super Rod & Good Rod)	Common
	Octillery (Super Rod)	Rare
	Magikarp (Old Rod & Good Rod)	Common
	Goldeen (Old Rod & Good Rod)	Common
In The Area 2's Rocks (Rock Smash)
	Shuckle	Common