This paper develops a model of regulated open access resource exploitation. The regulatory model assumes that regulators are goal oriented, choosing target harvest levels according to a safe stock concept. These harvest quotas are implemented by setting season lengths, conditioned on the industry fishing capacity. The industry enters until rents are dissipated, conditioned on season length regulations. Harvest levels, fishing capacity, season length, and biomass are determined jointly. Using parameter estimates from the long-regulated North Pacific Halibut fishery, predictions of these variables from the regulated open access model are compared to predictions that arise from the Gordon model.