I'd like to participate in one of those
big US ROFFian claves.
The question is which one to choose?

Well, not to denigrate the western clave, but the Penns clave is
probably a bit larger. Many of us speak binary, so we can use that as a
intermediate language. The accommodations are from covered hammocks and
tents to nicely outfitted cabins (that are really just fully-furnished
houses for rent). Also, we've yet to have a heart attack when the final
bill came (sorry Dave S., just had to say it). We have awards, prizes,
a really nice fly shop, everything from little brook trout creeks to big
brown trout rivers (both the water and the trout are big), and all the
bad scotch you can steal from Seidman's tent. Heck, we even have
pickled asparagus. The eastern US may be a bit cheaper to get to.
Penns isn't as storied as some of those western rivers, but I've found
that people will write more about a trip involving serious depredations
(bears, mountain lions, strange rangers) than they will about a trip
where they just caught fish all day, ate fine meals and slept soundly
all night.
Frank Reid