This field trip will examine the sequence stratigraphic framework and tectonic evolution of depositional systems within the Late Cretaceous Peninsular Ranges forearc basin, northern Baja California, Mexico. The Late Cretaceous Peninsular Ranges forearc basin is discontinuously exposed along the Pacific Coast of southern California and Baja California for a distance of almost 500 Km (Figure 1; Beal, 1948; Gastil et al., 1975). These strata were deposited along me east side of a west-facing forearc basin complex (Bottjer and Link, 1984) and onlap the Upper Jurassic to Upper Cretaceous Peninsular Ranges batholith (Beal, 1948; Gastil et al., 1975; Silver et al., 1975). The strata record an active tectonic history of alternating uplifting, downdropping and tilting of local basins, which has resulted in a complex sequence stratigraphic framework where models developed primarily from passive margin settings are not necessarily applicable.