The planet is described as having a frostbitten surface, indicating that Holdfast is likely a frozen world. The refuge on Holdfast is described as being a limestone cave with a broken Stargate and lit by weak bioluminescence bulbs. The caves were cut with laser drills and is warm and humid underground despite the surface of the planet being frostbitten. The caves contain hydroponics, machine shops and training rooms amongst other things needed for survival and have people from the Tau'ri, the Free Jaffa, the Pangarans and Langarans amongst others. (SG1: "Relativity")
In an alternate timeline, following the release of the Aschen bioweapon on Earth, the virus rendered 98% percent of the Tau'ri sterile and after jumping species to plants and animals, turned the Earth into a barren wasteland. As the situation on Earth grew chaotic with governments collapsing and people turning on each other, those who could escape off-world did so. Two of the places that the few surviving Tau'ri evacuated to were Chulak and Holdfast.
By 2032, with the virus having turned many planets into barren wastelands and a war between Anubis and the Replicators devastating what was left of the galaxy, Holdfast had become the headquarters of Commander-in-Chief Jack O'Neill, the leader of what remained of Milky Way humans. From Holdfast, Commander O'Neill led a guerilla war against the Aschen, but though the virus was long burnt out and gone, the effects were permanent and the Tau'ri and the peoples of thousands of other worlds faced extinction in less than a single generation. After discovering an outpost belonging to the Ancient Janus that contained a series of time travel devices, Holdfast was used as a base to launch incursions into the past in an attempt to alter the timeline and prevent the release of the devastating virus.