The significant potential for cellulose nanocrystals (CNCs) to be used in a wide variety of products is currently limited by a lack of complete characterization of their material properties. The objective of this research is to address this issue via complementary nanoscale experiments and simulation. In this paper we present findings from the first phase of the research. From the experimental perspective we report atomic force microscope measurements of the transverse elastic modulus of tunicate CNCs, and, using molecular dynamics simulation, we investigate the effects of model structure on predictions of axial elasticity. Careful consideration is given to understanding the uncertainty inherent in such measurements with the eventual goal of allowing for true sample-to-sample and modeling-to-experiment comparison.