This study investigated motivation in the context of L2 Chinese in the USA. A total of 120 college students took the survey and 27 of them participated in post-survey interviews. Through a mixed-methods design, the study captured interactions between motivation and the learning environment in the learning process. The results revealed six motivation factors, of which the "ideal L2 self" was the most powerful predictor for "intended effort," and significantly correlated with after-class activity engagement in which students committed actual time to learning. In addition, the "anti-ought-to self" significantly correlated with all the motivation factors and was also a significant predictor for "intended effort." It functions as an intrinsic motivation featuring the active agent role of the individual learner. Lastly, the learner's positive interactions with the learning context via self-regulatory strategies and accompanying procedural knowledge led to a positive experience, which sustained learning.