The Delvers Guild is not a guild in the feudal sense of the term. It is more of a group of rich, by Infran standards, and scholarly who believe that the Reach and the Farther hold riches or implements of power beyond anyone’s wildest dreams.
Not much is truly known about the Delvers, since most ‘members’ do not openly acknowledge their membership due to the Guild’s disreputable and frowned-upon goals. The common Infran knows two things about the Reach and the Farther: their names make sense geographically and they are dangerous. People who want to send common folks into their depths shouldn’t be trusted.