This article analyzes the portrayals of Spanish in The Squatter and the Don (1885), a novel written in English by Mara Amparo Ruiz de Burton, a Baja Californian who immigrated to Alta California at the time of its annexation to the USA in 1848 and became the first Hispanic American woman writer. Her novel had an ideological purpose, namely, to denounce the land dispossession of the Californios i.e. Hispanic settlers in California during the Spanish-Mexican period and to propose an alliance between the Anglo and Hispanic elites. It also had a financial purpose, since writing was for Ruiz de Burton one of many ways in which she attempted to achieve financial prosperity. The representation of language was thus dictated not just by linguistic or aesthetic considerations, but also by the author's interpretation of the conditions prevalent in late 19th-century California, where Spanish had become subordinate to English. Ruiz de Burton's positive attitude towards bilingualism is revealed in her portrayal of protagonists as proficient in both languages. Yet, her awareness of the biases and limitations of her intended Anglo readership is also evident in the fact that Spanish use in the novel is sporadic and restricted. Comparison of her literary and non-literary code mixing highlights some consistent differences between both text types providing additional evidence of Ruiz de Burton's purposeful manipulation of linguistic codes in her artistic production.