This trip was actually my second time in. The first being in in the Spring with the park very flooded, the San Juaquine river over it's banks, and the driveway submerged.
Part of the trip's intent was to try tracing the Trailmaster hike on Great Valley Grassland's Web site from the "other end". Beyond the first leg along the levee road, I saw no signs of the walk.
Regardless, it's a fun half day following the San Juaquine and blazing one's own path. If you fish, bring a pole, there's plenty of promising spots and few people using them.