From Dean Wilson at the Southwest Ceramic Typology Project:

Tohatchi Red-on-brown was defined by Reed and Goff (1998). This type developed out of early brown ware forms and represents the earliest painted type produced in the Colorado Plateau (Reed and Goff 1998; Reed and others 2000). Tohatchi Red-on-brown appears to essentially represent a painted brown ware and developed out of Obelisk Brown and Tohatchi Red. It is extremely rare, as it is present in a limited area where it appears to have quickly developed into early forms of La Plata Black-on-white which quickly spread across the Colorado Plateau. Tohatchi Red-on-brown has been identified in contexts in the Southern Chuska Valley and has also been noted in the Cove-Redrock Valley and Prayer Rock district in northeastern Arizona (Reed and others 2000). 

From Dean Wilson at the Southwest Ceramic Typology Project:

The production of this type was very short-lived probably spanning from about A.D. 550 to 600, and is the earliest painted type produced in the Colorado Plateau. Pottery illustrated as Tohatchi Red-on-brown include both examples resembling Obelisk Gray but with simple painted decorations as well as those exhbiting characteristics similar to those noted for La Plata Black-on-white but with designs executed in red paint, and thus seems to reflect a continuum of development between these two types as usually defined. Examples of painted pottery reflecting this shift in technological and decorative conventions seem to be represented by forms sometimes been placed into a Transitional Tohatchi/La Plata Black-on-white category. Pottery assigned to this category are most similar to pottery classified as La Plata Black-on-white, except for the application of desings in a clay/hamite pigment as identied for Tohatchi Red-on-brown.