Abstract The creation of a regional decomposition scoring system for western Colorado provides a model for the creation of regional systems. The development of a scoring system requires: (1) human remains, not proxies, (2) longitudinal observations, and (3) large sample size. First, an enhanced system (total body desiccation score; TBDS ) was developed through observations of 40 human remains. This effort produced a categorical scoring model augmented by qualitative categories of gross tissue change. The new model was tested with retrospective photographic packets. A sample of eight donors with data collected over 3 years was selected. Monthly data points over a maximum of a 3‐year period yielded 112 data points. Correlations between TBDS and accumulated degree‐days ( ADD ), and total body score ( TBS ) and ADD were approximately equal for a TBS below ~20, but the TBDS correlated better with ADD at higher TBS scores >20. The TBDS may be used to refine postmortem interval ( PMI ) models in areas where remains desiccate.