You cannot reach the river from the cache site. The only way into the gorge is if you boated from upstream. The river can be reached from the day use area Gray Falls Trail. This is a nice place to have a picnic too!
In 1914 a footbridge was built at this location to provided access to New River mining camps along the lower reaches of the New River and to the settlement of Denny. It was known as the New River Trail. The Denny settlement included produce and fruit farmers; the trail provided marketing opportunities to the coast (for Humboldt’s first Organic Farmers!).
In the 1970’s a group of Hippies used the bridge to set up a camp/commune at the confluence of the New & Trinity Rivers. A Forest Service Land Surveyor told me the bridge was in place until 1980 when the Army Corp of Engineers helicoptered the bridge parts away. I think you can see part of the footbridge still to this day at the bottom of the river in the gorge.
You can read more about this location in “Traveling the Trinity Highway” by, Ben Bennion & Jerry Rhode