What Will macOS 10.16 Be Called: Mammoth, Monterey, Skyline, or Something New?

Every year heading into WWDC, one question on many Mac fans' minds is what Apple will choose as the name for the next version of macOS. The tradition dates all the way back to the beginning of Mac OS X with its big cat names, and then in 2013 Apple shifted to Calfornia-themed names with the unveiling of OS X Mavericks.

macos 10 16 names
Back in the early days after the debut of OS X Mavericks, we discovered a total of over 20 California-themed trademark applications filed by various limited liability companies that were all but certain to be shell companies created by Apple to hide its identity.

Over time, some of the trademarks like Yosemite, Sierra, and Mojave were indeed used by Apple for its major Mac operating system updates, while trademark applications for many of the other names have been abandoned.

In last year's lead-up to WWDC 2019, we noted that of that original set of trademark applications, only four unused ones remained active: Mammoth, Monterey, Rincon, and Skyline. All four of those trademarks had been granted by the U.S. Patent and Trademark Office, and Apple was keeping them alive for potential use by filing successive extension requests.

Trademark recipients have up to 36 months from the date of approval to file a Statement of Use proving they are using the trademark in commerce, although they are required to file for extensions every six months during that period to keep that full window open.

Apple of course opted to name its 2019 macOS release Catalina, which wasn't one of the previously trademarked names, but in case Apple has opted to go back to its original list, we decided to check back on last year's trademark list to see if any of them remain protected.

Of the four, Rincon is no longer active, having been abandoned in September 2019 after its 36-month window expired. The other three remain active for now, with Apple's presumed shell companies continuing to file extensions as needed.

  • Mammoth, which is likely related to Mammoth Lakes and Mammoth Mountain, a popular area for skiing and hiking in the Sierra Nevada mountains, saw its trademark application approved in March 2019, and a second extension of the Statement of Use period was approved in March 2020. The full 36-month window won't expire until March 2022 as long as additional extensions continue to be filed.
  • Monterey, a historic city and popular vacation spot on the Pacific coast, has long been one of the most popular macOS name options among our readers over the years. The trademark was applied for by Asilomar Enterprises LLC in December 2013, but wasn't allowed until June 12, 2018. A fourth extension to Statement of Use window was granted just last week, and Asilomar will have until June 2021 to prove commercial use of the name, provided a final extension is requested in December of this year.
  • Skyline likely relates to the scenic Skyline Boulevard that largely follows the ridge of the Santa Cruz Mountains running south from San Francisco, and Antalos Apps LLC filed for a trademark on the name in December 2013. The trademark was allowed on March 20, 2018, and the fourth Statement of Use extension was granted in March of this year. The owner will have until March 2021 to prove use of Skyline in commerce, provided all necessary extensions are requested.

So what will macOS 10.16 be called? Mammoth, Monterey, and Skyline all seem like reasonable options, but we've also seen Apple turn to names that had not been previously rumored. In years when the new macOS version is viewed as more of a refinement of the previous version rather than a leap forward, Apple has used names that bear relationships to the previous ones, such as going from Yosemite to El Capitan and Sierra to High Sierra.

With macOS 10.16 again seeming to be more of a refinement release, could we see something like macOS Channel Islands (the island group that Catalina is a part of) or macOS Avalon (the only city on Catalina)? Or with Apple reportedly set to begin transitioning to its own Arm-based chips for its Mac lineup, could it shift gears to something completely different? Whatever it ends up being, we'll know one week from today.

Related Forum: macOS Big Sur

Popular Stories

Aston Martin CarPlay Ultra Screen

Apple's CarPlay Ultra to Expand to These Vehicle Brands Later This Year

Sunday February 1, 2026 10:08 am PST by
Last year, Apple launched CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. Nearly nine months later, CarPlay Ultra is still limited to Aston Martin's latest luxury vehicles, but that should change fairly soon. In May 2025, Apple said many other vehicle brands planned to offer CarPlay Ultra, including Hyundai, Kia, and Genesis. In his Powe...
iOS 26

iOS 26.3 and iOS 26.4 Will Add These New Features to Your iPhone

Tuesday February 3, 2026 7:47 am PST by
We are still waiting for the iOS 26.3 Release Candidate to come out, so the first iOS 26.4 beta is likely still at least a week or two away. Following beta testing, iOS 26.4 will likely be released to the general public in March or April. Below, we have recapped known or rumored iOS 26.3 and iOS 26.4 features so far. iOS 26.3 iPhone to Android Transfer Tool iOS 26.3 makes it easier...
Apple Logo Black

Apple's Next Launch is 'Imminent'

Sunday February 1, 2026 12:31 pm PST by
The calendar has turned to February, and a new report indicates that Apple's next product launch is "imminent," in the form of new MacBook Pro models. "All signs point to an imminent launch of next-generation MacBook Pros that retain the current form factor but deliver faster chips," Bloomberg's Mark Gurman said on Sunday. "I'm told the new models — code-named J714 and J716 — are slated...
Apple MacBook Pro M4 hero

New MacBook Pros Reportedly Launching Alongside macOS 26.3

Sunday February 1, 2026 5:42 am PST by
Apple is planning to launch new MacBook Pro models with M5 Pro and M5 Max chips alongside macOS 26.3, according to Bloomberg's Mark Gurman. "Apple's faster MacBook Pros are planned for the macOS 26.3 release cycle," wrote Gurman, in his Power On newsletter today. "I'm told the new models — code-named J714 and J716 — are slated for the macOS 26.3 software cycle, which runs from...
iOS 26 Home Feature

Apple Gives Final Warning to Home App Users

Tuesday February 3, 2026 8:55 am PST by
In 2022, Apple introduced a new Apple Home architecture that is "more reliable and efficient," and the deadline to upgrade and avoid issues is fast approaching. In an email this week, Apple gave customers a final reminder to upgrade their Home app by February 10, 2026. Apple says users who do not upgrade may experience issues with accessories and automations, or lose access to their smart...

Top Rated Comments

jayducharme Avatar
74 months ago
Mac OS Cluster****
Score: 40 Votes (Like | Disagree)
MakeAppleAwesomeAgain Avatar
74 months ago
I don't care as long as they don't release new features and just focus on getting macOS stable again.
Score: 40 Votes (Like | Disagree)
nfl46 Avatar
74 months ago
macOS Snow Catalina

?
Score: 39 Votes (Like | Disagree)
Skylar. Avatar
74 months ago
macOS High Catalina.

Unoriginal joke, I know.
Score: 33 Votes (Like | Disagree)
Lounge vibes 05 Avatar
74 months ago

MacOS Weed
Yeah, because after a year with Catalina, Weed is what we need
Score: 22 Votes (Like | Disagree)
casperes1996 Avatar
74 months ago
I'm hoping for macOS Redwood
Score: 21 Votes (Like | Disagree)