A general term referring to the second of the five main cultural historical stages defined for the archaeology of southwestern parts of North America: broadly the period c.100 bc–ad 600, succeeding the Archaic and preceding the Colonial. The Pioneer Phase represents the earliest agriculturalist communities. The period is characterized by the gradual introduction of maize and other tropical cultigens, gradually transforming the resident hunter‐gatherer populations into sedentary agricultural communities. The several different environments in the area produced adaptations with recognizable subdivisions, one of the most notable of which is the Hohokam of the southern Arizona desert, which dates from the very end of the 1st millennium bc. The first Hohokam Phase includes the cultivation of crops using irrigation canals, the first use of ceramics in the area, and sub‐rectangular pit‐houses in small villages.