Upon completion of this quest the fortress will be phased in with Orcs getting cozy in it. Now we can get some garrison resources and hidden treasure...
On the same level Durotan is on here, go to the small side room in the south at 45, 64. Go inside and turn to face the door, you will see some supplies on the side. Next in the small side room on the inner circle (52, 29) there's a <Repairs> NPC named "Wrong Knick", in this room hanging by some ropes (look up) are some more supplies. (You have to jump up the pile of crates to reach it). Another room on this level, located (48, 64) with the Battle Pet Trainer and Stable Master, go in look up and jump on some crates to more supplies.
On the second level, on the outside portion of it where you fought Doorog (the big Gronn), the area with the lava pool; head to the western interior wall of the courtyard and there's a chest labeled "Doorog's Secret Stash" (37, 69). On the interior, near the eastern side at 70, 62 there's the <Innkeeper> Havi the Sullied, inside this room "on the right side" are more supplies (Ogre Booty)...and on the left side behind some crates, some more! In the large, circular room on this level at 49, 20 there's a cubby with more Ogre Booty. Another small room at 46, 19 are more supplies high up you must jump on crates to get. On the western side at 38, 30 another room/cubby with supplies/treasure, etc. Another room/cubby at 52, 49 with treasure hanging from a rope, hop on them crates again!
Next go up the ramp to the very top level of the fortress where you fought the big, bad Ogre. Go up the ramp, no chain climbing this time. Go to the big throne, behind it are some more hidden supplies (31, 61). If you are unable to get behind the throne then jump on the throne's seat, jump on its left arm (as you're facing the back) and walk up as far as you can, move your camera around and you'll be able to open the chest via cogwheel.