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Olivia S. Glazner Cassil

Oklahoma City +1 405 591 3513


All Oklahoma State Courts 
U.S. District Court for the Northern District of Oklahoma
U.S. District Court for the Western District of Oklahoma
U.S. District Court for the Eastern District of Wisconsin 

PRACTICES Litigation \ Oil and Gas

Olivia S. Glazner Cassil is an experienced litigator with a broad range of expertise. Olivia’s litigation practice primarily involves complex commercial disputes. Her experience covers all manner of oil and gas litigation, construction disputes, UCC/sale of goods matters, probate and estate administration, and all types of contract disputes, both in prosecution and defense. Olivia also has in-depth experience on appellate matters. Olivia is passionate about her work representing federally-recognized Indian tribes in federal and tribal court litigation, with special emphasis on asserting rights to water and other natural resources. She has also provided general counsel services to tribal nations and tribal healthcare and community organizations on matters including employment law (including TERO), healthcare, contracts, housing, and cultural and religious protections. This experience includes drafting tribal codes and policies in compliance with applicable state and federal regulations (such as HIPAA), with special emphasis on protecting tribal sovereignty. During law school, Olivia obtained certification in indigenous peacemaking, served as a law clerk for Oklahoma Supreme Court Justice Noma Gurich, and was the recipient of the Henry Kent Anderson Human Services Award. She was also the Articles Development Editor of the American Indian Law Review. Olivia is a citizen of the Cherokee Nation of Oklahoma. She serves on the Board of Directors of Lyric Theatre of Oklahoma.

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