In February of 2010, a week of avalanches closed the Salang Pass, the high road through the mountains north of Kabul. What the Snow Kept grew up around that winter. The medic who speaks in the poems is invented, but the pass is real, and so is the cold, and so is the particular arithmetic of keeping someone alive long enough to hand them to someone who can do more. I did not set out to write poems. I set out to keep an account of what a deployment does, to the people who go and the people who wait. The poems are what the account became. This is the book that started the press.