The "white rose" is Esther Morse, a young woman traveling west along the Oregon Trail. One morning when she has wandered away from her wagon train, she encounters Waupee, who reveals that her husband, Black Eagle, is pursuing Esther in order to marry her.
After warning Esther, Waupee disappears. Black Eagle, who was lying in wait during the conversation between the two women, captures Esther before she can return to her camp. Unbeknownst to Esther, Black Eagle has been hired to kidnap her by Elelu Thomas, a Mormon who is also traveling west.
In spite of Elelu's plans, Black Eagle intends to double cross the Mormon and marry Esther himself. Waupee insists that Black Eagle has put her aside in favor of Esther. Esther, however, believes that Black Eagle has kidnapped her preparatory to stealing from the wagon train. When Black Eagle makes his intentions plain, Esther is astonished.
Black Eagle keeps his rendezvous with Elelu in the canyon, and during the staged conversation between the two, the Mormons traveling with Elelu attack the Indians in earnest. During the ensuing struggle Esther escapes. As she is wandering alone through the mountains, she meets a friendly Indian named Osse'o. After her experiences with Black Eagle, Esther is understandably wary, but Osse'o provides her protection and offers to escort her safely back to her people. On their way, they encounter Waupee and Waltermyer, a man sent to rescue Esther. Together they witness a struggle between Black Eagle and Elelu. Black Eagle kills Elelu and shoots Osse'o with an arrow before dying himself. Esther's feelings toward Osse'o soften as she helps to nurse him. It turns out that Osee'o is not an Indian but a white man in disguise, and by the time they arrive at Esther's camp, Osse'o and Esther are engaged.