Warchief's Command: Feralas!

Route to Feralas from TB hoofin' it without flying mount or flightpaths and no areas with high level mobs:

Go north from Thunderbluff to Stonetalon Pass. Take the pass into Stonetalon Mountains. Head towards the coast. Head south on the road at 35, 79 into Desolace. Travel through Desolace to the road east of Gelkis Village. That road takes you into Feralas. There are flight paths on this route so be sure to pick them up.

You can do both this quest and The Wilds of Feralas
1. Pick up Warchief's Command: Feralas! and hand it in first.
2. Don't pick up any further quest from Konu Runetotem.
3. Now you can pick up The Wilds of Feralas

This quest is a Breadcrumb quest.

Breadcrumb quests are quests that, even though you did not complete them and they were available at some point, have become unavailable permanently after certain conditions were met. If this happens to you, and you're a completionist, this quest can be marked as excluded in the Wowhead quest tracker if you are no longer able to complete it.

This quest becomes unavailable permanently, if either of the following conditions are met:

• 
  
• Tears of Stone is completed.
  This is one of the quests available in the quest hub that this quest points to, and is also considered a follow-up to this quest. Completing this quest will make all zone introductory quests leading to this npc, including this one, unavailable.
• 
  
• Warchief's Command: Feralas! is completed.
  This is a Warchief's Command quest leading to this zone. You can only complete this quest, or the Warchief's Command quest, not both. Completing the Warchief's Command quest will therefore make this quest unavailable.

Examples of Breadcrumb quests and conditions making them unavailable:

• Warchief's Command quests.
  They become unavailable if your character's level is too high, and the Warchief's Command board sends you to a different npc/zone.
• 
  
• Zone introductory quests.
  This also includes Warchief's Command quests. These quests are often started in a certain lower level zone, and they direct you to the next zone. If there are several of these, including the Warchief's Command, directing you to the same zone/npc, completing one will mean the others become unavailable.
• 
  
• Quest hub introductory quests.
  These are quests that direct you to the next quest hub in a zone. If you've already completed the quests in that quest hub, the quest directing you to it may become unavailable.
• 
  
• Follow-up quests.
  These are uncommon, but still appear in older zones that have not been changed much in recent expansions. Sometimes a follow-up quest of quest X is available before you complete quest X. If you complete that follow-up quest and go back to the quest X giver, you may encounter the error 'You do not meet the requirements for that quest', leaving you unable to start it or turn it in.

Note: A quest being unavailable does not necessarily mean it's unavailable permanently. If you have not met the aforementioned conditions, and the quest is still unavailable, then you may have missed certain required quests that precede this one, or you do not meet the requirements in some other way. Always verify this before excluding this quest.

based on MaxTheDragon's post