We describe a logical framework based on a denotational characterization of mobile process semantics. The logic builds on a trace model that associates to processes the sequences of actions one can observe from their behaviors. The basic predicates of the logic are properties about such sets of sequences. In order to support the reasoning on branching structures, a notion of structured location is used to decorate the observations made on process behaviors. The same notion of location is also employed to address some critical issues of mobile-calculi such as freshness and scope extrusion. We also develop a proof normalization procedure to increase the abstraction level of the logic.