The ancestral Caddo constructed social and cultural landscape is marked by earthen monuments or mounds, persistent places on the landscape from when they were built to the present day. They were visually striking because of the Caddo’s use of sediments of markedly different color in mound construction. They were deliberately set at key places on the landscape, some natural such aa at low water river crossings, or near the confluence of different streams, while others were of cultural selection along corridors of travel, such as along ancestral trails between settlements and earthen mound centers.
There are at least 115 known earthen mounds in East Texas. Most have only one or two constructed earthen monuments, but there are several that have as many as seven or eight mounds, including the Hudnall-Pirtle site in the Early Caddo period, the Jamestown site in the Middle Caddo period, the Horace Cabe site in the Late Caddo period, and the ca. 16th century seven-mound complex in the Big Cypress Creek basin at the closely-associated Harroun, Dalton, Chastain, and Camp Joy sites. The Caddo peoples that lived in East Texas between ca. A.D. 900-1690 created a long-lived historical landscape that was tied to specific places, beliefs, and cultural practices, including community centers marked by earthen mounds, plazas, as well as associated non-mound community cemeteries and many dispersed settlements; the majority of non-mound community cemeteries at the mound centers postdate ca. A.D. 1440.
The mounds used by Caddo peoples tied them to specific and special ritually charged places, and they also represent distinct period of social and cultural change, from one form of community-building to another, where after ca. A.D. 900 people became tied to these places. The building and rebuilding of mounds, and the building and rebuilding of the special structures that stood on the mounds, likely represent a principal and deliberate step towards Caddo communities creating their own history, ritual and political practices, and sacred places. Caddo mound centers and monuments were spiritual places as well as places of social, economic, and political practice and interaction. Even though not all mound centers served the same purposes, they likely were linked within broader and probably hierarchical communities.
The highest densities of earthen mounds are in several counties along the Red River in the Post Oak Savanna as well as along the Sabine River and tributaries in the Pineywoods, and in the Pineywoods in the Big Cypress Creek basin. Multiple mound sites of Caddo construction are best represented in the Red River basin from the Pineywoods to the Post Oak Savanna and on the north and south sides of the Sabine River in the Post Oak Savanna and Pineywoods biotic regions of the upper and mid-Sabine River basin. There are no known multiple mound sites in the Sulphur River basin, only a few widely separated multiple mound sites in the Neches and Angelina River basins, including one with a “fire temple,” and a series of multiple mound centers in the upper, mid- and lower Big Cypress Creek basins.
Differences in the character and distribution of Caddo sites with multiple mound (of varying functions and constructions) between the Red and Sabine River basin communities and those in the Big Cypress and Neches-Angelina drainage basins suggest that there were diverse socio-political communities and ritual practices among the ancestral Caddo between ca. A.D. 900-1690, with the more complex and possibly hierarchically ranked communities present primarily along the length and breadth of the Red and Sabine river basins in East Texas.
Twenty-four percent of the mound sites were constructed in Early Caddo times, 29 percent in Middle Caddo times, and 47 percent in Late Caddo period times. Early Caddo period (ca. A.D. 900-1250) mounds are most common in the Pineywoods or the Post Oak Savanna along the major streams. In the Middle Caddo period (ca. A.D. 1250-1440), earthen mounds are distributed in the main stream drainages, but are apparently most widely distributed in the Post Oak Savanna along the Red River, and along the western margins of the Pineywoods in the Sabine River basin. Middle Caddo multiple mound centers in these areas include perhaps the premier mound center at this time at the Jamestown site in the Sabine River basin. On the Red River, there is a significant multiple mound center at the T. M. Sanders site; one of the two mounds there is a platform that covered four levels of buried structures, and the other is a burial mound with single and multiple internments and an array of associated funerary objects, many of exotic origin.
The number of Caddo earthen mounds in East Texas increased by 60 percent from Middle Caddo to Late Caddo period times (ca. A.D. 1440-1690). The 37 known mounds dating to the Late Caddo period are best represented on the Red River and in the Pineywoods in the Big Cypress Creek and Sabine River basins. Along the Red River in East Texas the most important mound center and village community was at the ca. A.D. 1500-1691 Hatchel site occupied by a Nasoni Caddo community. The large 30 ft. tall primary platform had eight levels of buried and/or burned structures, often superimposed over one another. In the Pineywoods, earthen mounds of Late Caddo age were key parts of local Caddo communities that had dispersed mound centers, non-mound community cemeteries, and villages in the Big Cypress Creek and Sabine River basins. The mounds have buried and burned structures in their deposits, or had burned structures capped by mound sediments and some had a large shaft tomb dug through a burned structure, which was then capped with mound sediments. The 15th through 17th century Pine Tree Mound site is the most impressive of the Titus phase mounds known in East Texas, as the site has three mounds, a plaza, associated habitation areas, and at least one large community cemetery. Archaeological information indicates that the Caddo’s construction and use of earthen mounds for monumental structure platforms, as well as mounds that capped burned structures buried below mounds, and for burial mounds of elite personages, did not continue past ca. 1691.