He is known for his roles in Waiting for Guffman, The Last Days of Disco, Scream 3, and the miniseries Frank Herbert's Dune and Stephen King's Rose Red.

[citation needed] Keeslar appeared in Waiting for Guffman, The Last Days of Disco,[2] Scream 3, and the miniseries Frank Herbert's Dune and Stephen King's Rose Red.

He established a strong working relationship with South Coast Repertory in Costa Mesa, California, where he performed plays and staged readings.

Keeslar retired from acting in 2010, citing financial difficulties and a lack of work, and went on to pursue a career in science.

He wrote an essay about his struggles with his acting career and subsequent decision to enroll at Portland Community College.