I stayed at Leonard Harrison for a week one year, back when it didn't have showers...so we made it a point to go to ole bull and fish the kettle every other day! Anyhow, I digress, LH is quite a fine park, and if you don't mind the hike up and down the "Turkey Trail" it's got good fishing. The Turkey Trail is a beast though, especially with fishing gear. It's also near the tiadaghton access road which is good fishing, but you can access it easily via the rail trail.
All in all I would take the fam to LH, lots to do and see, plus it looks like it has top notch facilities now.