From the descriptions of the Pursuits related to Mount Tam:
The community of Tranquility was closed down due to mass rioting during the Pale Wars. All that remained were EMC personnel.
Mount Tam was once a rural, backwoods territory until the arks arrived and the EMC turned it into an inter-species community.
Project Tranquility was the UN’s proposed inter-species social experiment where Votans and Humans lived side by side.
Some Tranquility residents were bussed out of town, never to be heard from again, creating rumors of a secret agenda behind the scenes.
”There’s a lot of rumors going around about the community that used to be in Mount Tam. The truth may never be found. At least not until someone is fool enough to sift through the rubble to find it. From what I’ve heard, though, I hope that never happens.”
— Captain Noah Grant, E-Rep Officer
Mount Tam is an eeire, terraformed landscape where mutants infest the ruins of a defunct inter-species community once called Tranquility.