Base Cochise is located at the far northwest corner of the map. Unprepared Rangers entering Base Cochise (that is, without at least Pseudo-Chitin Armor and Energy Weapons) will be eradicated by incredibly lethal robots before they even get close to breaching the doors. Base Cochise can be entered only with the proper Secpass, which can be obtained at the Sleeper Base.
 How Do I Get There
Decisions, decisions! You can get to Base Cochise via two main methods:
- Walking up to the front gate and knocking.
- Flying the Helicopter from the Guardian Citadel.
If you aren't sure about your party holding up against some of the toughest baddies in the game, you might want to take the helicopter route, at least, if you find that the Guardians aren't as tough as the Cochise robots. The helicopter will knock out some of the perimeter defenses on the way in, and you can enter from the roof. Then again, if you're looking for a good scrap, you might want to walk up and crawl the perimeter instead, and soak up all that high-value experience!