Chinook salmon are historically native to the Guadalupe River watershed as proven by a recent ancient DNA sequencing study of salmonid remains excavated from Mission Santa Clara and dating to the mid-nineteenth century. Of 55 salmonid vertebrae analyzed three samples had DNA sequences indicating Chinook salmon ("Oncorhynchus tshawytscha"), the rest were steelhead trout ("Oncorhynchus mykiss"). These findings are consistent with earlier documentary records indicating the local presence of migrating salmon in the ‘'Rio Guadalupe'’ dating as far back as the 18th century. Much older archaeological remains of salmon were found dating through A.D. 300 in the lower watershed in what is now north San Jose. On February 22, 1904 the San Jose Daily Mercury (now the San Jose Mercury News) reported "Several large salmon and steelheads have become stranded in the holes, and after the water has subsided they have become the prey to boys. Several large salmon have been captured even in the city limits." Both steelhead trout and Chinook salmon continue to spawn and rear in the Guadalupe River, making San Jose the southernmost major U. S. city with known salmon spawning runs, the other major cities being Anchorage, Seattle, Portland, and Sacramento. From 1992–1994 a genetic study of mitochondrial DNA in 29 fish showed that some have haplotypes not found in Central Valley wild or hatchery salmon, but found in the Russian River. Two subsequent analyses found that chinook salmon in the Guadalupe River are mainly fall run Central Valley chinook, but also that some were genetically similar to lower Columbia River basin salmon. Chinook salmon are adept at colonizing neighboring and even distant streams and rivers, as evidence by the recent finding of juvenile Chinook salmon from the Klamath River in the Napa River. In 2012, the Santa Clara Valley Habitat Plan reported that Chinook salmon currently spawn in the Guadalupe River and its tributaries, as well as Coyote Creek. Because Chinook spawn in early winter and juveniles may migrate to the ocean in their first spring, Chinook are able to use habitats that turn very warm or have low water quality in summer.