Per capita rates of entry are commonly used to measure regional entrepreneurial climate. Yet entry rates vary widely by industry and tend to mirror existing regional specializations. Without controlling for industry mix, factors associated with regional differences in entry may describe the industry base rather than entrepreneurial climate. This study finds that while industry mix explains a potentially large portion regional variation in entry, it does not radically alter the relative standing of the most highly ranked regions. Most of the factors commonly associated with the regional entrepreneurial climate remain significant after purging the data of industry mix effects. However, a number of commonly-cited factors—namely, educational attainment, homeownership, University R&D, and unemployment—were found to be contingent upon industry structure.