Complex sentence: Yet Chacoan complexes showed little evidence of being defended or defensively sited high on cliff faces or atop mesas, and only several minor sites at Chaco evidence the large-scale burning that would suggest enemy raids.
Split into simpler sentences: Yet Chacoan complexes showed little evidence of being defended or defensively sited high on cliff faces or atop mesas. Only several minor sites at Chaco have evidence of the large-scale burning that would suggest enemy raids.