The neural and vascular anatomy of the posterior fossa and bony skull base is of interest to both neurosurgeons and otologists charged with the evaluation and management of patients demonstrating lesions in this region. Despite well described approaches to pathology in this area, access to the lower basilar artery and clivus remains a significant challenge. This report highlights the pertinent anatomic details of the fossa, describes the bony dimensions relevant to surgical access, and reviews two unconventional approaches to the lower basilar upper vertebral artery union.