Where to find SHIELD caches in Marvel's Avengers
The easiest way to find a SHIELD cache is to play the Stark Realities mission. This mission is located in the Pacific Northwest region on the War Table map and requires a minimum power level of 35. After starting the mission, follow the river to the left. Finally, you will cross a small canyon. Continue until the signal locator appears in the upper left corner of the screen below your current target.
The Signal Finder won't give you the exact destination of the SHIELD cache, but it will help you find it. It shows you how far away you are currently from the cache and will beep faster the closer you get. Use the signal locator to focus on the cache location. You are looking for a small circular object that protrudes from the ground. It's very easy to miss, but it's near a tree surrounded by shrubs and foliage.
After interacting with the object, a secret entrance will reveal itself. Head inside to find a few chests with some good loot inside. There is one chest in particular that you are looking for. It's marked with a SHIELD logo on the cover and you can find it on the right after you walk down the entrance ramp. Inside you'll find a Vault resource that will provide you with the coordinates of a Vault mission. You can return to the Quinjet from here or complete the mission - either way your progress is saved.
You can now complete the Vault mission you unlocked to continue the Vault Onboarding mission chain.
