Start: Hornsby Station
End: Richmond Station
Total distance: 136km
Strava link
I followed the Colo River from where it flows into the Hawkesbury upstream as far as you can cycle. The road along the river is beautiful and peaceful. You have to walk the last 3km through private property to get to the Colo Meroo campground in the national park.
A shorter version of this trip would start and finish in Windsor or Richmond.