https://www.ancestralknowledge.org/

Dont know if this is too far for you but we did 2 weeks of camp here for 2 summers and my kid loved it.

This is a great rec- thank you!

If you are interested in an after school hiking/nature group, Grown Outdoors has awesome classes: https://grownoutdoors.com.

OP here- thank you! These are both really helpful.

Girl Scouts is girl-led, so every troop is really going to be different. It might be a great option - just make sure to talk to the leader about what her vision is.
Scouting America is more proscriptive than Girl Scouts, so you might be more guaranteed to find an outdoor-focused Cub scout troop.

Cub Scouts, Scouting America is now Co-Ed and there are a lot of Co-Ed Packs.

I’m looking for recs for organized activities to get DD, rising first grader, into nature/Rock Creek park on weekends in the fall. We hike as a family/with friends but hoping to find a regular weekend activity where she can be with a bigger group of kids too. Girl Scouts came to mind, but when looking into it, their marketing these days seems to lean into “entrepreneurship” — do they also just explore the woods? Woodend has a day camp that looks exactly up our alley but I’m not seeing a regular weekend option. Appreciate any recs!