A backward masking function relating target detection to masker delay was generated for a bottlenosed dolphin in an active echolocation target detection task. The masker was triggered by each outgoing echolocation click and could be temporally adjusted from coincidence with the target echo to delays of 700 μs. The animal reported target condition using a go/no‐go response procedure. A modified method of constants was used to present the four masking delay intervals. Results indicated that 700‐ and 500‐μs delays had little effect on target detection. However, as the delay was reduced to 100 μs, detection dropped to chance performance. The calculated 70% detection threshold corresponded to a delay of 265 μs. The results are discussed in support of the view that time separation pitch (TSP) may be an analytic mechanism used by the dolphin to discern various within‐echo target attributes rather than an analytic mechanism for determining target range.