Bright was an authority on the native languages and cultures of California, and was especially known for his work on Karuk, a Native American language from northwestern California. His study of the language was the first carried out under the auspices of the Survey of California and Other Indian Languages. He was made an honorary member of the Karuk tribe—the first outsider to be so honored—in recognition of his efforts to document and preserve their language which led to its revival. Bright was also known for his research on the native American languages Nahuatl, Kaqchikel, Luiseño, Ute, Wishram, and Yurok, and the South Asian languages Lushai, Kannada, Tamil, and Tulu.