Wallace Line to the west of the Philippines. Wallace's studies in Indonesia demonstrated the emerging theory of evolution, at about the same time as Joseph Dalton Hooker and Asa Gray published essays also supporting Darwin's hypothesis. Understanding of the biogeography of the region centers on the relationship of ancient sea levels to the continental shelves. Wallace's Line is visible geographically when the continental shelf contours are examined; it can be seen as a deep-water channel that marks the southeastern edge of the Sunda Shelf which links Borneo, Bali, Java, and Sumatra underwater to the mainland of southeastern Asia. Australia is likewise connected
Wallace, Idaho the Montana state line. East of Wallace, the "Route of the Hiawatha" (rails-to-trails) and the Lookout Pass ski area are popular with locals and tourists. Wallace came into being on a river plain where four streams and five canyons converge onto the course of the South Fork. The earliest known white interest in the area was the construction of the Mullan Road, which followed the South Fork from near Cataldo almost to the pass that crossed into Montana. John Mullan did observe promising quartz outcroppings along their route when he passed through in late 1859. However, he later frankly stated