We present a novel approach for (written) dialect identification based on the discriminative potential of entire words. We generate Swiss German dialect words from a Standard German lexicon with the help of hand-crafted phonetic/graphemic rules that are associated with occurrence maps extracted from a linguistic atlas created through extensive empirical fieldwork. In comparison with a character n-gram approach to dialect identification, our model is more robust to individual spelling differences, which are frequently encountered in non-standardized dialect writing. Moreover, it covers the whole Swiss German dialect continuum, which trained models struggle to achieve due to sparsity of training data.