Ocuilan is Barlow's Province 4. It is described on page 12 of the Matrícula and on folio 34 recto of the Codex Mendoza. The following maps and table are all from Barlow (1949).

Location Map. The province of Ocuilan is shown in green.

 
Barlow's Map of the Province. The dashed line is the modern boundary between the Estado de México and Morelos. The volcano is now better known as El Nevado de Toluca.

 

Tributary Pueblos

1. Temazcaltepec#
2. Zoltepec#
3. Coatepec
4. Tonatiuhco
5. Tequaloyan
6. Tenantzinco
7. Ocuilan
... Çincozcac (not located)

 

Modern Location

1. Temazcaltepec, Méx.#
2. Zoltepec, Méx. #
3. Coatepec Harinas, Méx.
4. Tonatico, Méx.
5. Tecualoya (Villa Guerrero), Méx.
6. Tenancingo de Degollado, Méx.
7. Ocuilán de Arteaga, Méx.
... ?

Key

# Town indicated as a tributary in a source other than the Codex Mendoza.

* The appelidos of the modern place names are from Castillo Farreras (1997).

? Location uncertain