Near edge x-ray absorption fine structure (NEXAFS) and density functional theory (DFT) calculations have been applied to study the interaction of 1-epoxy-3-butene (EpB) with the Ag(110) surface. Three EpB adsorption states have been identified: a multilayer state stable to 165 K, a chemisorbed EpB state stable to 215 K, and a highly stable oxametallacycle intermediate stable to nearly 500 K. Carbon K-edge NEXAFS spectra for EpB multilayers are in excellent agreement with the time-dependent excitation spectrum calculated by DFT for the EpB molecule, permitting detailed analysis of the excited state orbital structure. This combined experimental/theoretical approach indicates that chemisorbed EpB is weakly bonded to the surface with its vinyl group oriented at a small angle to the surface. NEXAFS spectra obtained at normal and glancing incidence for the oxametallacycle intermediate are fully consistent with the DFT-predicted geometry of this intermediate. These results demonstrate the importance of both theory and experiment in determining the identity, structure, and reactivity of complex surface intermediates such as these recently discovered oxametallacycles.