Science writer Sevigny (Mythical River) documents the 1938 survey of the Colorado River by the first two women botanists seeking distinctive plants growing in the Grand Canyon. Shoving off in June, Elzada Clover, Lois Jotter, and an expedition leader with three boatmen traveled 600 miles down the Colorado, facing danger when running the rapids, hunting for and documenting hundreds of plants, and arriving at Lake Mead 43 days later. Woven into the narrative are mentions of previous river expeditions, starting with John Wesley Powell’s in 1869. Elizabeth Wiley adroitly narrates this account, employing a dramatic flair when sharing the women’s letters and diaries and creating separate voices for each as they describe stops along the way, problems encountered, and breathtaking sights seen. Wiley’s empathy for the painful limits imposed on women scientists in the 1930s is palpable (botany being one of the few sciences open to women at the time). Wiley also infuses a feeling of frustration in passages that speak of other societal limitations based on sex and race. VERDICT An amazing trip down an awe-inspiring river, and a powerful tribute to two pioneering women of science.