Garmire was last seen in a residential area in San Francisco, California on September 26, 1990. He gave the deed to his property to an acquaintance and wrote notes about suicide prior to disappearing. He told one friend that if he took his own life, no one would ever find his body. Garmire left behind all his personal belongings, including his clothes, motorcycle and boat, when he disappeared. His brown Ford truck was located on October 6, in a yellow zone on Folsom Street near Eighth in San Francisco.

After Garmire's disappearance, over $4,000 was charged to his credit cards, starting on October 5. The signature on the credit slips did not appear to be Garmire's, however. He enjoys hunting, backpacking, and boat building. Authorities believe Garmire committed suicide, but his case remains unsolved.