Hiked 4 mile Rose River Circuit Trail to Dark Hollow Falls and Trail. Very nice streamside hike almost all the way. Long descent and steep ascent but waterfalls and stream views made it extremely rewarding. Exposed geology, aesthetic appeal, clean, not heavily trafficked until Dark Hollow Falls. Afternoon 4 mile hike along Rapidan River to Pres. Hoover's Rapidan Retreat. Long forest descent before getting to the streamside trail. Retreat was interesting enough, but I didn't love it. Rose River 4.5. Rapidan 4.0.