I aimed to avoid rivers that have relations by only tagging the smallest/simplest ones, but will double check that.
Thanks!

good catch, I have been inconsistent with that

https://elevation.nationalmap.gov/arcgis/services/3DEPElevation/ImageServer/WMSServer?FORMAT=image/png32&TRANSPARENT=TRUE&VERSION=1.3.0&SERVICE=WMS&REQUEST=GetMap&LAYERS=3DEPElevation:Hillshade Multidirectional&STYLES=&CRS={proj}&WIDTH={width}&HEIGHT={height}&BBOX={bbox}

Is this the same as osm.org/relation/14205621 ?

This can be verified on street signs visible on mapillary

It's possible that these rules have changed since your edit!

The webpage referenced says "The horse trails to the west of Quinsnicket Road as identified on themap link below as being Zone "A" shall be used exclusively for equestrian use. Those trails the the east of Quinsnicket Road as identified on the map linked below as being Zoned "B" shall be multi-use and may be utilized for mountain biking activities."

This implies the opposite of your edit: no bikes allowed in Zone A and both bikes and horses allowed in Zone B.
See also https://riparks.ri.gov/parks/lincoln-woods-state-park

I did not remove the names from trails when I created relations for them; it was unclear to me if they are relevant to rendering.

Does a collection two dozen rocks that people climb and write books about as a single entity make a good relation?

Will do!