In many near-surface applications, detailed sub-surface characterization is important. Characterization often is obtained using ground-penetrating radar (GPR) or shallow seismic-reflection (SSR) imaging methods, depending upon depth of interest and surficial geology. Each method responds to different physical properties; thus, each may produce different images of the same near-surface volume. By incorporating the two methods, we generated a cross-section of the subsurface at an alluvial test site and identified the depths of three interfaces accurately to ¿5 cm. We present here experimental results and examples of SSR and GPR images obtained along the same traverse, showing coincident and noncoincident reflections from multiple interfaces within 3 m of the surface. ¿ 2001 American Geophysical Union