Plural internal reduplication in Washo has generated much interest in the phonological literature. This study presents a novel analysis that unifies the treatment of a set of seemingly disparate aspects of this plural reduplication pattern (e.g. variation in the placement and size of the reduplicant, contrastive vowel length in stressed syllables, post-tonic gemination, and vowel-length inheritance in reduplication), relying on the interaction between constraints on weight assignment, affix anchoring and stress assignment. In particular, the odd placement of the plural reduplicant in roots with internal consonant sequences and the restricted distribution of long vowels in Washo can be attributed to a previously unnoticed emerging preference for heavy stressed syllables on the surface. The results of this study have implications for theories of reduplication and theories of weight phenomena in general.