Parkhill Prairie Trail is a 1.9 mile loop trail located near Farmersville, TX and is good for all skill levels. The trail is primarily used for hiking and is accessible year-round.
I took my daughter to this trail to do a quick shakedown hike as preparation for a summer backpacking trip. This is definitely more of a nature preserve than a park with trails. Most of the trail was knee-to-waist high grass, as were the common areas. The only way to differentiate the trail from the field was to walk between old treads where they must run a mower or tractor at the beginning of the season, and watch for occasional marker posts. It was more like bush whacking than hiking. The long trail that runs to the observation area to the north measured out at 1mi out and back and did offer some really nice views.
This park is probably paradise for nature observers, since there was a lot of flowers and bird/insect activity. Didn't see any snakes, but I'm sure they are in abundance. But it's not really for hikers or anyone wanting to use the open space for an outing.