A combined experimental and numerical study correlating indentation stiffness with mineralization and microporosity was performed on mineralized turkey leg tendon. Two distinct tissue morphologies were distinguished by quantitative backscattered electron imaging and called "circumferential" and "interstitial" zones. These two zones showed different tissue organization, microporosity, and mineralization. Stiffness, measured by microindentation, was also different in the two zones. The mean field method of modeling of mineralized collagen fibers was employed to explain the differences.