Molecular phylogenetics have revolutionized microbial ecology, allowing microbiologists to ask questions about microbial activity within the environment without the need for cultivation.  Nonetheless, comparative phylogenetics are only a useful predictor of metabolic activity when there is high identity with a previously cultivated and characterized species.  As a result, cultivar libraries remain a critical component in the study of metabolic activity, particularly in little understood environments such as caves.  The species cultivated from these environments demonstrate a tremendous breadth of metabolic activity, from antibiotic production to polyaromatic-hydrocarbon breakdown.  Unfortunately history, timing and pure technical challenges have also conspired to make cave cultivar libraries some of the most hyped, least characterized and most under-utilized microbiological collections.  Even so, the tremendous industrial potential of these collections is leading to academic and industrial partnerships to overcome these limitations, which include the inadequacy of standard cultivation techniques, sampling permits, landowner rights and the National Park Service’s benefits sharing regulations.