Working memory is the cognitive capacity for temporarily holding information in mind for processing or use, and supports most of our actions and behaviors. Although activity in the rodent prefrontal cortex (PFC) is necessary for successful rodent spatial working memory utilization, rodent spatial working memory tasks do not always evoke robust PFC delay encoding of retrospective spatial information. We hypothesized that, like in nonhuman primates (NHPs), increasing spatial optionality might facilitate the detection of retrospective spatial encoding in the PFC. We therefore used an automated 8-arm radial maze to implement a novel match-to-sample rodent spatial working memory task with seven options on each trial, and recorded calcium activity in PFC neurons during task performance. We found that, during the delay phase of the task, PFC neurons indeed encoded retrospective spatial representations of the arm visited in the preceding sample phase, at both single-cell and population levels, in a distributed manner. Also, in accordance with recent NHP work, these representations were evident in considering dynamic, heterogenous neural activity, and in considering a low-dimensional subspace, where time-invariant retrospective spatial information could be decoded. Thus, this work reveals that in rodents, freely-moving, spatially-demanding behavioral paradigms can evoke distributed spatial working memory representations in the prefrontal cortex, with reasonable similarity to the working memory representations observed in nonhuman primates.