In the Pokémon Sun and Pokémon Moon Special Demo Version, a woman at the east end of the road in front of the Hau'oli City Pokémon Center will guide the player here. She will also guide the player back to the city from the trail. At the top of the trail, the player will encounter a "mysterious" man in a red shirt who will give the player Stardust to transfer to their full game. The player can revisit him, but the man will have no further gifts for them.
The Mahalo Trail is a narrow trail that winds upward through mountainous terrain. The trail cuts through the terrain in a switchback fashion, forming steep walls to either side. The top of these walls often rises into more cliffs and hills, or grows wild with a variety of trees and bushes. In some places, stout statues dot the sides of the trail, with some statues positioned atop the walls of the trail as well. It leads to the Plank Bridge, a wooden bridge spanning a wide ravine with a river running through it. Near the start of the game, Nebby destroys the bridge, but after the player becomes ChampionSM/defeats Ilima at Hau'oli Cemetery during Mina's trialUSUM, it will have been restored.
In Pokémon Ultra Sun and Ultra Moon, after defeating Ilima in Hau'oli Cemetery during the course of Mina's trial, the player can return to Plank Bridge to meet Lillie, who asks that the player take Nebby, now a SolgaleoUS/LunalaUM, in their care. They can then battle Nebby, and in the process, give it any nickname.
In the demo, smashable rocks block the trail, requiring Tauros Charge to pass. In the demo only, the trail eventually comes to a dead end where four statues sit in a square, each facing the center.
Mahalo Trail appeared in A Mission of Ultra Urgency!, where Ash and his classmates confronted a Buzzwole there during their first mission as the Ultra Guardians. While the others tended to healing a Snorlax that Buzzwole had drained of energy, Ash started battling Buzzwole in order to catch it. With its amazing strength and speed, Buzzwole was more than a match for Ash's Pikachu. However, it soon turned out that Buzzwole was more into watching Kiawe and Ash flexing with it than battling. Using this distraction to their advantage, the group was then able to capture Buzzwole with a Beast Ball, allowing them to take it to Melemele Meadow to be returned to its home world through an Ultra Wormhole.
In the manga
Mahalo Trail in Pokémon Adventures
In the Pokémon Adventures manga
Mahalo Trail debuted in The Decision and the Tournament of Six, where Moon and Lillie traveled there after Nebby escaped from Lillie's bag and ran off. Upon arriving, they found Nebby being attacked by a group of wild Spearow. Moon stepped in to save Nebby, but Nebby caused an explosion that broke the bridge they were standing on, causing both to fall into the water. They were saved by Tapu Koko, who caught Moon and Nebby and brought them to safety.
Mahalo is a Hawaiian word meaning "gratitude" and "thanks".