We examine the results of 1 year of near-continuous measurements for a 128-km over-the-horizon C-band coastal propagation link. The link extends between Dam Neck, Virginia (16 km south of Virginia Beach), and Wallops Island, Virginia (approximately 150 km southeast of Washington, D.C.). The objectives of this effort are to explore the different mechanisms of propagation through an analysis of several case studies and to assess the statistical connectivity over the 1-year period. Case studies involving the linking of environmental information and measured signal levels are analyzed. Propagation factor levels due to evaporation ducts, surface ducts, and scattering from irregularities of the refractive index in the common volume are determined. Cumulative distributions of the measured propagation factor for the annual, fall-winter, and spring-summer periods are presented. Conditional and absolute distributions of propagation factor time durations are also presented and analyzed. It is demonstrated that during the spring-summer period, received signal levels were consistent with ducting and not with troposcatter. The fall--winter levels may be due to troposcatter from irregularities of the refractive index. The months giving the smallest and largest propagation factors were January and June, respectively. ¿ 1999 American Geophysical Union