[citation needed] By age 12, Thunderhorse reports he had been exposed to six languages (English, Italian, Latin, French-Canadian, Anishinabemowin, and Quiripi) by his relatives.
"Thunderhorse's teachings are a mishmash of Native American religion and other New Age favorites, such as Tibetan Buddhism, Taoism, and Ancient Druidism," writes anthropologist Lisa Aldred.
[10] In June 2014, shortly after being paroled to a halfway house in Houston, TX, Thunderhorse pulled off his electronic monitoring anklet and fled to the New Haven, CT, area.
Thunderhorse fought extradition to Texas, but the Supreme Court denied his claims of sovereign immunity and ordered him returned to TX in January 2015.
He wrote exclusive columns on prison law in Easyriders, Biker Lifestyle, Iron Horse, Guild Notes, and Voice for the Defense.
[15] Thunderhorse has written columns about legislation and prison reform in the Daily Texas (UT-Austin Law School paper) and the Houston Post[16] In 1990, Dallas Morning News reporter Mark McDonald wrote that "the state also knows Mr. Coppola [Thunderhorse] as one of the most formidable legal opponents it has ever encountered, a jailhouse Clarence Darrow, a self-taught prison lawyer of incomparable skill and persistence.
Eventually, Attorney General Richard Blumenthal indicated he would file for a permanent injunction after Thunderhorse pointed out that the original donors of the land did so with the stipulation that the Parks be used for the public (precluding a golf course for the wealthy).
This led to an investigation by ADVOCACY, Inc.[citation needed] In late 2004, Thunderhorse filed suit in Pro Se under the RLUIPA (Religious Land Use and Institutionalized Persons Act) after TDCJ defendants reportedly violated three previous out-of-court settlements.
Four of his illustrations appear in Voices of Native America[23] and he designed the cover for his only authorized biography, Following the Footprints of a Stone Giant: The Life and Times of Iron Thunderhorse.
A permanent exhibit of Iron's maps and portraits reside at the Quinnipiac Dawnland Museum in Guilford, Connecticut, while a large collection of his work remains at the ACQTC National Office in Milltown, Indiana.
Thunderhorse has written bilingual poetry in numerous Algonquian language dialects and has published many scholarly papers on linguistics in the Dawnlander, the ACQTC Literary Journal (annual).
In 2006 he published a 295-page revised and expanded edition, A Complete Guide for Learning, Speaking, and Writing The PEA-A Wampano-Quiripi R-Dialect (QTC Press, ACLI Series).