Traumatic brain injury (TBI) is a leading cause of trauma-related death and disability, affecting approximately 69 million people globally each year [1]. While TBI research is primarily focused on brain tissue mechanics, vascular injury is present in nearly all clinically significant cases [2]. Despite this, cerebral vasculature is rarely included in computational models of TBI, and when it is, there is no standard for the biomechanical properties applied [2,3]. Existing studies of cerebral vessel stiffness have predominantly been limited to the middle cerebral artery and bridging veins, where significant longitudinal variability has been observed [2,4]. Consequentially, the mechanical and microstructural heterogeneity of intracranial arteries and veins across vessel type, branching level, and brain region is not well understood. This study aims to characterize regional variation in the biomechanical properties of the cerebral vasculature. We will present our ongoing work combining region matched mechanical and immunohistological data of cerebral arterial and venous tissue from a goat model. Samples include trunk and cortical branches from the Circle of Willis (anterior and middle cerebral arteries), cortical veins, and bridging veins from the temporal and frontal regions. Local mechanical properties are assessed using quasi-static, small-strain micro-indentation with a spherical indenter (radius of 125 μm). Concurrent immunohistochemical analysis will be performed to measure collagen, elastin, and cellular composition. Ongoing analysis aims to identify what, if any, significant differences exist in vascular mechanics and microstructure as a function of vessel type, branching level, and brain region. This will inform future studies of vessel damage and provide guidance for the integration of mechanically representative vasculature into computational models. [1] M. C. Dewan, et al. Estimating the global incidence of traumatic brain injury. J. Neurosurg., Vol. 130, pp. 1080-1097, 2018. [2] K. L. Monson, M. I. Converse, and G. T. Manley. Cerebral blood vessel damage in traumatic brain injury. Clin. Biomech., Vol. 64, pp. 98-113, 2019. [3] H. Duckworth, et al. A Finite Element Model of Cerebral Vascular Injury for Predicting Microbleeds Location. Front. Bioeng. Biotechnol., Vol. 10, 860112, 2022. [4] N. Famaey, et al. Structural and mechanical characterization of bridging veins: a review. J. Mech. Behav. Biomed. Mater., Vol. 41, pp. 222-240, 2015.