Considering all US untowered airports, what is the furthest distance that E2 airspace (dashed magneta line) projects from the airport?
Best candidate so far--

Sheridan County Airport-- Sheridan, Wyoming-- KSHR
Page E-92 in the "Airspace Designations" document

The E-2 airspace extends 17.6 (nautical) miles southeast of the airport-- and also 16 miles northwest of the airport  -- last amended 5/31/12

http://vfrmap.com/?type=vfrc&amp;lat=44.769&amp;lon=-106.980&amp;zoom=10