Clark grew up in southern California. He studied at UC Davis and completed a Master of Fine Arts in poetry at the Iowa Writer's Workshop. At Davis, Clark drummed for the band Buick, whose album Sweatertongue was released by Lather Records in 1992. He also drummed for the Popealopes, and is featured on their album Slowest Eye, released by Italy's Helter Skelter Records.

In 1995, he graduated from the Iowa workshop and moved to San Francisco, where he wrote poetry and edited a zine, Faucheuse. He also worked for Wilsted & Taylor, a book design studio in Oakland, California.

Clark's first book, The Little Door Slides Back, was a 1996 winner of the National Poetry Series award. It was published by Sun and Moon Press in 1997, and reprinted in 2004 by Farrar Straus and Giroux. John Yau, writing in Boston Review, said that Clark evoked "a fragile, interior world largely lit by the moon, cheap paperbacks, and noir movies, a place in which predicaments and paradoxes abound." Farrar Straus Giroux also published Clark's second collection, Music and Suicide, which received the 2004 James Laughlin Award. John Beer in Chicago Review said it was "most clearly an advance from his debut" though not "without missteps, lapses into a perfunctory pastiche of high decadence". The book was notable, in the context of contemporary American poetry, for receiving several negative reviews, by Ron Silliman, Steven Evans of The Poker, Peter Campion of Poetry (in which Clark is compared to dictator Kim Jong Il and artist Jeff Koons), John Palatella in The Los Angeles Times, and Troy Jollimore in the San Francisco Chronicle, among others. One review, published at cosmoetica.com, went so far as to call for Clark's death.

In June 2006, Clark and Geoffrey G. O'Brien released 2A, an experimental collaboration in poetry.

In 2009, Turtle Point Press published Ruins, a limited edition book that Clark wrote, illustrated, and designed.

Clark's book design studio, Quemadura, is based in Ypsilanti. He has composed book covers and interiors for, among others, Flood Editions, Leon Works, Kelsey Street Press, the Jargon Society, Essay Press, Wake Forest University Press, Ahsahta Press, Dalkey Archive, Wave Books, Farrar Straus Giroux, Black Square Editions, City Lights Books, the Ulrich Museum of Art, and MOCAD (Museum of Contemporary Art Detroit).

In January 2008, Publisher's Weekly wrote: "Clark has become one of poetry's most prolific and influential book designers, whose distinctive treatments...characterized by spacious covers; hip, angular fonts; varied elements that elide into one another...a frequent poetry reader could recognize from a distance."

Clark lives with poet Christine Hume and their daughter in Ypsilanti.