As Swenson's longtime companion and literary executor's title suggests, this biography centers on the poet's literary evolution. Knudson does describe key characters and events— Swenson's Utah youth as oldest child in a large, devout Mormon family; her escape to N.Y.C. as a young woman during the Depression; her hand-to-mouth existence as a struggling poet unwilling to compromise enough to hold a job; years of rejection slips; volatile relationships. None of these is portrayed in depth (Swenson's feelings toward her family are left particularly enigmatic), but Knudson offers enough revealing detail to give a sense of this fiercely independent woman's character. Best, she quotes many poems that illuminate Swenson's experiences; and describes the act of creation (``Her way of working was to begin poems with lines that seemed to leap out of thin air'') and the way she thought about it (``She'd had fun choosing the adjectives to pour into `Sun,' but she'd weakened the poem with too many of them''). Five of her poems are published for the first time here. A provocative, insightful portrayal of a fine contemporary poet, much of whose work has particular appeal for young people. List of Swenson's books. B&w photos & index not seen. (Biography. 10- 14)