Green’s Dictionary of Slang

(drugs) any powdered narcotic.

1933		Ersine Und. and Prison Sl. 62: reindeer dust. Snow, cocaine.
1942		Berrey & Van den Bark Amer. Thes. Sl.
1959		J.E. Schmidt Narcotics Lingo and Lore 167: Smell the reindeer dust – To inhale finely powdered cocaine.
2001		ONDCP Street Terms 18: Reindeer dust — Heroin.
2013		T. Dorsey Riptide Ultra-Glide 22: Coke [...] lay lines, cut rails, hitch the reindeer, chase the dragon.