There are 4 Hiller UH-12E4 aircraft on the U.S. registry that TailWiki has a page for. Every one is built from the public FAA record — year, serial, engine, home base, and registration history — and owners and pilots add photos, trips, and stories on top. The ones listed here were built between 1966 and 1976.
N64741
1976 Hiller UH-12E4
Harlowton, MT
N501HA
1966 Hiller UH-12E4
Middletown, DE
N48220
Hiller UH-12E4
Ridge Spring, SC
N705WA
Hiller UH-12E4
Wilmington, DE