Were timbers transported to Chaco using tumplines? A feasibility study

Abstract

Between 850 and 1200 CE, approximately 200,000+ large timbers were transported >75 km to Chaco Canyon using only human power. Researchers have proposed various load-carriage methods, speculated about how many porters would be needed and their speed of transport, but none have conducted empirical investigations. Here, we explore the feasibility of long-distance timber transport using tumplines, a technology well-evidenced in Chaco’s archaeological record. Two authors trained themselves to use tumplines and together carried a 60 kg timber 25 km with the timber oriented transverse to the walking direction. Total elapsed time was <10 h and walking speed averaged 4.5 km/hr. Individual walking speed with a 30 kg tumpline load was only ∼10 % slower than the preferred unladen walking speed. Timber transport to Chaco using tumplines is clearly feasible. We close by considering the implications of tumpline timber transport on the socio-political dynamics of Chacoan society.