General hybrid systems can be difficult to verify due to their generality. To reduce the complexity, one often specializes to hybrid systems where the complexity is more manageable. If one reduces the modeling formalism to ones where the continuous variables have a single rate, then it may be possible to use the methods of zones to find the reachable state space. Zones are a restricted class of polyhedra formed by considering the intersections of half-planes defined by two variable constraints. Due to their simplicity, zones have simpler, more efficient methods of manipulation than more general polyhedral classes, though they are less accurate. This paper extends the method of zones to labeled Petri net (LPN) models with continuous variables that evolve over a range of rates.