Dusty Wind Hill
You can find Dark Stumps and their weaker cousins, regular Stumps, in the North Rocky Mountain: Dusty Wind Hill. This is just one of several maps in the North Rocky Mountain series. This map is two locations up from the north exit of Period. It contains a task board that occasionally has quests for players. You use Dusty Windy Hill to access Board Land to the west or Mini Rocky Road to the east.
Mini Rocky Road
To the east of Dust Wind Hill is another map where you can hunt Dark Stumps. This location also includes the more challenging Axe Stumps, which drop firewood and axes with wood. Winston, an archaeologist, is a non-player (AI) character who resides in this map. He has several quests that require you to hunt the monsters in the surrounding area and talk to other NPCs on Victoria Island, especially those in Perion.
Training Centers
If you play a lower-leveled (below level 20) character who is just learning about skills, you can enter the Magician or Warrior Training Centers by talking to the NPCs outside of Ellinia or Perion. The Training Centers are special locations that aren't on the world map and the NPCs will provide special quests that you can complete within the centers. Through these quests, you can gain experience and beginner's skills.
Pre-Big Bang
Before the changes due to the Big Bang story arc in January 2011, there were more places to hunt Dark Stumps. The stumps could be found in several maps to the north east of Perion, including Rocky Road I, II and III. Dark Stumps hung out in the mountains west of Perion, too. In addition to this, Dark Stumps lived in maps around Ellinia. You could fight them at The Forest South of Ellinia, The Tree That Grew II, The Tree That Grew III and the Tree Dungeon, to the north of Ellinia. Many of these maps no longer exist, have been modified or became the basis of new maps after the Big Bang event.