The Pecos Classification is an early Southwestern cultural-temporal framework which emerged from the Pecos Conference of 1927 (Kidder 1927). This classification is based principally on changes in architecture, pottery and and other forms of material culture.
The Pecos Classification is largely applicable only to parts of the Anasazi culture area - not the whole Southwest. Some changes have been made to the original definitions but the the Pecos Classification still forms the basis of chronological division for the Anasazi culture.
San Juan Basin
|1863-present||Reservation Navajo||Reservation Navajo||US Territorial||PV|
|1770-1863||Cabezon||Cabezon||Mexican/Santa Fe Trail||Cabezon||PV|
|1650s-1770||Gobernador||Gobernador||Post Pueblo Revolt||Gobernador||PV||Gobernador Polychrome|
|1400-1540||Classic Pueblo IV||PIV|
|1100-1400||PIII||McElmo/Mesa Verde PIII||Coalition Pueblo III||Largo-Gallina||Late PIII
|Mesa Verde||Mesa Verde B/w, indented corrugated (rock & sherd)||Major re-population|
|McElmo||McElmo, indented corrugated (rock/sherd/sand)||Major depopulation/severe drought|
|900-1100||Arboles PII||Bonito PII||Late Developmental Pueblo II||Early PIII
|Late Bonito||Chaco-McElmo/Gallup B/w, indented corrugated (sand)||Major greathouse constr. north of San Juan River||Major population increase, then decrease|
|Classic Bonito||Gallup B/w, indented corrugated (sand & trachyte)||Major greathouse constr.||Major depopulation. Varied climate: drought, major surplus|
|Early/Classic Bonito||Kivas appear|
|Early Bonito||Red Mesa B/w, narrow neckbanded (sand).||Small-house aggregation & sharp number increase. Greathouses appear in numbers in San Juan Basin||Major population rise, rise of turquoise industry/crafts, corn ubiquitous in sites. Water control systems appear.|
|700-900||Rosa Piedra PI||White Mound PI||Early Developmental Pueblo I||Late PI
|Early Bonito||Kiatuthlanna & Red Mesa B/w, Lino Gray & Kana'a Neckbanded||Above ground slab house sites; small to moderate size?||Shift from dry to wet period.|
|White Mound||Whitemound B/w, Lino Gray||Classic above ground slab row house sites; small to moderate size.1st greathouses appear.||Major increase in storage facilities|
|White Mound||Whitemound B/w, Lino Gray||Deep pithouses, dispersed.||Sparse storage facilities?|
|500-700||Sambrito BM III||La Plata BM III||Alameda BM III||Late BMIII
|La Plata||La Plata B/w, Lino & Obelisk Grays||Shallow pithouses, dispersed.||Moderate storage facilities (surface cists)|
|La Plata||La Plata B/w, Lino & Obelisk Grays||Shallow pithouses. Two aggregated great communities with great kivas appear.||Moderate storage facilities (surface cists)|
|100-500||Los Pino BM II||Basketmaker II||Rio Rancho BM II||Late BMII
|brownware||Obelisk Gray & brownware||Unknown.||Unknown.|
|BC800-AD100||En Medio||En Medio|
|3200-1800||San Jose||San Jose|
With the coining of the Hohokam name for the culture of southern Arizona, Winifred and Harold Gladwin proposed a new system in 1934 (Gladwin and Gladwin 1934). The Gladwins named the Hohokam periods Colonial, Sedentary, Classic, Recent, and Modern.
Archaeological activity in the 1930s brought to light another major regional culture - -the Mogollon (Gladwin and Gladwin 1935; Haury 1936) which shared its origins with the Hohokam.
A fourth major subculture - Hakataya or Patayan is included in the chart below. This designation brings together several groups which occupied common areas of the Southwest and descended from common ancestors. Hakatayan cultural divisions are less well-defined than those of the other Southwestern peoples.
The chart above reflects the idea that the San Jose tradition continued on as the Anasazi and that the Cochise people continued on as the Hohokam and Mogollon; this progression is debatable.