In the Chinook Jargon, stick meant anything of wood, from a ship's mast to a forest; hence "Stick" Indians were the forest dwellers as opposed to the people of the coast.
1913  Coast Indians . . . found their profits from fur trade with the interior, or "Stick Indian" as he was known, because he came from the land of forest. . . .
1958  All along the banks were camped the Stick Indians, dirty, ragged, and sick-looking, smoking salmon and offering to buy or sell everything and anything from those who floated by.
1963  . . . snowshoes are known only as a strange accoutrement of the "Stick Indians," who inhabit the area north from the Blackwater basin, and with whom the Chicotin sometimes come in contact.