Success in the women's visually impaired super-G in Sochi was the team's first ever gold on snow and ended a long wait for victory on the slopes in the Winter Olympics and Winter Paralympics since the events started in 1924 and 1976 respectively.
Gold for Gallagher and Evans capped a long and challenging journey to the top for the duo after their paths first crossed following Gallagher's efforts in Vancouver four years earlier.
The Northern Irishwoman, who has oculocutaneous albinism, had been a late developer after first trying skiing as a teenager.
After being the first on the track, the pair endured a nervous wait following their run but only Russia's Aleksandra Frantceva could get close and she still finished off their time with one minute 28.94 seconds.
Gallagher told BBC Sport: "It was nerve-wracking but I'm delighted with the result.
"I have to thank Charlotte for getting me to the line. We just threw ourselves at it. I prayed for the strength to ski and have fun."
Evans and Gallagher were awarded MBEs later in the year for services to the sport for people with visual impairment and the latter most recently won a silver medal at the 2019 World Para Alpine Skiing Championships.