Theory: Maple Treeway's Location

Abstract
Wii Maple Treeway is located around the Blue Streamer Region (Autumn Mountain in particular) from Paper Mario: the Origami King.

Arguments

 * Argument 1: Maple Treeway & the Blue Streamer region are two of the only autumn-themed locations found throughout the Mario series.


 * Argument 2: Both appear to be set in locations that are in a perpetual fall, with orange leaves year-round. This is unlike other autumn-themed areas we’ve seen, such as Dinosaur Land and cups in Mario Sports Mix.


 * Argument 3: a remix of Maple Treeway’s music plays in Shogun Studios’ Tranquil Pipes Teahouse. This is clearly an intentional nod to the track.