Her mother is Diane Harrison, whose name appears on enough environmental petitions and park-restoration sign-in sheets to wallpaper a supervisors' chamber. Growing up in that orbit, Arieann says, meant activism felt less like a calling and more like the furniture — always there, a little in the way. "I told myself I wasn't going to do this," she said, not unkindly. "I watched what it took out of my parents."

What changed is a little harder to pinpoint than a single conversion moment, which is maybe why her story is more interesting than the standard-issue origin narrative. She didn't get radicalized by one oil spill or one city council vote. It was more cumulative — a particular lot on Potrero that kept flooding, a stretch of Precita Creek that ran the color of rust two summers in a row, conversations with neighbors who had stopped being surprised by those things. Somewhere in there, the furniture started to look load-bearing.

Now she's doing the work: attending the meetings, building the coalitions, learning which bureaucratic pressure points actually move and which ones are decorative. Her focus has stayed hyperlocal — specific parcels, specific waterways, specific blocks where the soil or the drainage or the tree canopy tells a story about what's been deprioritized for how long. She is, in this sense, very much her parents' kid, even if she arrived at it sideways.

What's different, she'll tell you, is that she came in with her eyes open about the cost. She saw the long hours and the grinding incrementalism before she signed up for them. That's not nothing.

Anyone walking past the Precita Park bulletin board this week would see her name on two different flyers — one for a creek cleanup, one for a planning meeting about that low-lying lot. The clipboard is out.