The reason why my dissertation thesis focused on causeways goes back to 1998. On the final day of my field work at Tz’unun, the field director Clark Wernecke showed me the tunnel of EP7. On that tour he told me that they were interested in having someone studying the causeway(s) at the site. This triggered my interest in these features. I returned in 2000 and 2001 in order to map greater portions of the site. Later I changed project and geographical area despite a brief attempt to expand the causeway study to other sites in the western Belize area. There were several reasons for this change and one of them was the fact that the site had too few causeways. In the Cochuah region where I ended up I worked with nine causeways during my dissertation period 2002-2006 (two additional causeways were found in 2008). A major difference between the causeways in the Cochuah region and at El Pilar is that the latter had more water management features. The reason is probably due to the greater topographical differences between various features and the greater amount of rain run-off this area had to manage.
There is only one securely identified causeway at El Pilar. The Bryan & Murphy Causeway (BMC) is 390 m long, 30 m wide and runs almost 90 degrees west of north from the north-western side of Plaza Copal, between EP10 to the south and EP9 to the north. It is similar to causeway I at Xunantunich, which consist of double-walled stone parapets, roughly 1,5 m wide and 0,7 m high. The exterior parapet walls at Xunantunich follow the undulating ground surface and the interior parapet maintains a constant height of one or two stone courses (40-60 cm).
A massive ramp connects Plaza Copal and BMC but there may be stairs about half way down the slope. Excavation at the top, has revealed a clay ramp and the cobble fill that was used to extend Plaza Copal to the west. A 4 square meter trench at the top of the ramp that connects the causeway with Plaza Copal revealed a clay surfaced ramp, with a 12 degree slope that covered a clean cobble fill, dated to the Late Formative period. A long 1 m wide trench have been laid out across the causeway, just below Plaza Copal, but only the parapets were found. The northern parapet was two meters wide and roughly made. These may have been built within a short time and were heavily plastered. There were at least two plaster surfaces.
Located just north of the causeway is the LDF chert site which is a very large mound of chert tool production debris.
My survey in 2001 located breaks in the parapets of BMC which earlier had been neglected (the earlier maps show the parapets as complete features). Since the terrain slopes gently in a northern direction, water would have flowed out through the northern parapet breaks. Where the causeway reaches its lowest point, there is a channel with stone lining. The creek bed disappears and there may be a subterranean channel of modest size. To the west of this creek channel is the foot of a low and heavily quarried hill. The causeway parapets continue up the slope. The southern parapet seems to end (or start, depending on the perspective) in a quarried slope.
The end of the northern parapet is more interesting. A few meters west of the parapet is a small and badly looted mound that almost seems like a continuation of the parapet. West of this mound is the quarried hill. A mound slightly separated from the end of the parapet has been found at other sites in the western Belize area, such as at X-ual-canil.
There is only one structure associated closely with the causeway and that is an L-shaped structure along the north side of the causeway just below Copal. A household consisting of two structures are located south of the easternmost of the south parapet breaks. Indications of water flow were evident.
There had been indications of a second causeway near Pilar Poniente (the so-called “off-set causeway system”). However, it is doubtful that this feature can be called a causeway. It has only one parapet, 165 m long, which on its eastern side has an extended platform. This parapet also goes in a east-west direction. but is not as straight as the BMC. The “Pilar Poniente” parapet has two breaks, very close to each other. The westernmost of these breaks is located at the foot of a low hill that supports a large plazuela group. There is a creek bed running through it and water may have flown from the top of the hill.
A third and fourth parapet identified in 2001 are only 35 and 50 m long, but they run in north-south direction west of Pilar Poniente. They are on flat ground and are about 0.5 m high. They may be similar to the features that can be seen roughly 500 m north of Plaza Lec where there are several 20-30 m long linear or curvilinear mounds which I suspect are piles of rock from clearings of agricultural fields. They might be boundary walls. A similar feature may be a very low, but 30 m long linear mound that was located east of Kum. I was unable to map this feature within the current time frame.
Another 160 m long linear feature heads out from the eastern side of EP8, continues in an eastern direction down the slope and up another slope to meet a small plaza group located on top of a heavily quarried hill. At the lowest point along this linear feature there seems to be a break which may have been the outlet for water moving dowhill. It is doubtful if this structure should be called a causeway, since it appears to be similar to a dam or a wall.