Go back to 49ers. The donors and fans were fine with 49ers. A small group of politically motivated students, liberal arts teachers, and admins used a historical guilt power play and no one on campus had the gall to stop it.

If you are saying a physical mascot who is a goldminer (though there were many Hispanic, Chinese, and Free Black goldminers) is not an option: plenty of physical mascot options that are unique are available. I always lean towards minor league baseball absurd names as being the best:
Sea Dogs - port/sailing history
All the local birds, some by themselves, or add a an adjective like Sandy or Super or a color in front of them like Golden or Yellow: Surf Scoters, Kestrels, Sandpipers, Godwits, Grebes, Oystercatchers, Willets, Gulls, Jaegers (too easy of a tie in with Meister), Shearwaters, KingFishers, Buffleheads, Whimbrels, Yellow Warbler, Yellowthoats!, Turnstones, NightHerons