OS X 10.9 was named 'Mavericks' after a surfing location in Northern California approximately 2 miles from shore outside Pillar Point Harbor. OS X 10.10 looks to be named after Yosemite National Park or El Captain, a rock formation in the park.
In April, a few possible names were trademarked by Apple's shell corporations including Yosemite, Redwood, Mammoth, California, Big Sur, and Pacific.
MacRumors has now discovered an additional set of names registered in Trinidad and Tobago that appear to be linked to Apple. The names include Sequoia, Mojave, Sonoma, and Ventura.
At this point, the full list of known trademarks Apple has registered for includes Yosemite, Redwood, Mammoth, California, Big Sur, Pacific, Diablo, Miramar, Rincon, El Cap, Redtail, Condor, Grizzly, Farallon, Tiburon, Monterey, Skyline, Shasta, Sierra, Mojave, Sequoia, Ventura, and Sonoma.
Apple will unveil the new features in OS X 10.10 starting on Monday. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.