Lewis Barrett Welch was born in Phoenix, Arizona on August 16, 1926 and moved with his mother and sister to California in 1929 after his parents divorced. He enlisted in the Army Air Corps in 1944 but never saw active service. He worked for a period before attending Stockton Junior College, where he developed an interest in the works of Gertrude Stein.
In 1948, Welch moved to Portland, Oregon to attend Reed College. There he roomed with poets Gary Snyder and Philip Whalen. Welch decided to become a writer after reading Gertrude Stein's long story "Melanctha." Welch wrote his thesis on Stein and published poems in student magazines. Her influence upon him would shine through in many things that he would write throughout his life.
Welch moved to New York City after college, where he worked writing copy in the advertising industry. Welch was said to have come up with the advertising slogan,"Raid Kills Bugs Dead", but others have questioned this claim.The product's advertising tagline was created by the advertising agency Foote, Cone & Belding where Welch had worked for a time.
During that time period, Welch started to display emotional and mental problems and went to Florida to take a course of therapy.
He then went moved on to the University of Chicago, where he studied philosophy and English. In Chicago, he joined the advertising department of Montgomery Ward. He was working there at the time of the famous poetry reading at the Six Gallery in San Francisco that launched what was to become known as the San Francisco Renaissance.
Wanting to get back to poetry, Welch applied for a transfer to Montgomery Ward's Oakland headquarters. He returned to California, lived in Nevada for a short time, and returned to San Francisco in 1963, where he taught at the University of California Extension Poetry Workshop. After the return to California, he started to really get involved in the San Francisco literary scene. He soon gave up advertising and earned a living driving a cab while devoting more time to writing. He became an active participant in Beat culture, living at various times with Snyder and Lawrence Ferlinghetti. In 1960, poet Lenore Kandel met Welch and Snyder, who introduced her to many people in the Beat movement.
Welch, like Stein, composed poems that play with grammar, but his also often included imagary. In his work, he explored nature, pop culture, and spiritual practice. He was often grouped with the Beat poets, and Jonah Raskin described Welch as “a postmodern Walt Whitman” in the San Francisco Chronicle.
Jack Kerouac based his character Dave Wain in his novel Big Sur (1962) on Welch. In 1968, Welch signed the “Writers and Editors War Tax Protest” pledge, vowing to refuse tax payments in protest against the Vietnam War.
He had a common-law relationship with Polish refugee Magda Cregg. He acted as the stepfather to her son Hugh Anthony Cregg, III, better known by his stage-name Huey Lewis.
On May 23, 1971, he walked out of poet Gary Snyder's house in the mountains of California, leaving behind a suicide note. He had carried a stainless steel heavy-frame Smith & Wesson .22 caliber revolver. His body was never found. His friends from the Ananda Commune and the Nevada County Sheriff's Department conducted a huge search for Welch, with no results. The search was ended on May 31, 1971, after everyone concluded he was not to be found.