Good day and welcome to the forum!
IMO it seems there is confusion of whether the point of interest is the sign or the park visually represented by the sign.
Further highlighting that you are submitting the Martin’s Run Wetland Complex, itself as a park/outdoor space, may alleviate the scenario. Describing the leisure activities for visitors can be crucial for the description.
Adding links to show that these leisure activities is also good. The current link does show the restoration efforts made and what looks to be a trail. IMO while these are good for the environment, you should hone in on the human intractability of the space. The chronolog program you mentioned seems like a leisure activity that can prove this point.
One other note is to differentiate this from a similarly named reserve that is not open to the public according to their website. While reserves are good for the environment, keep in mind that we look towards human intractability when accounting for the mentioned historical/cultural significance. A reserve that does not encourage visitors would not be eligible as player activity may disrupt the restoration efforts.