I was a camp director and counselor for a program here in Arizona. We'd do short trips, 3-4 days, with kids from local schools.
I have a few take away a that have stuck with me 15 years later
using established camp camp grounds was extremely helpful, especially if they have a cafeteria. We'd have 50-80 kids and food prep was very difficult using just camp grills and fires. We reached out to local camp sites and groups and could frequently get very reasonable rates.
volunteer/staff to kid ratio was very important, this helped a lot. It also helped that all the counselors had roles and responsibilities laid out. Cook, medical, transportation, who taught what program, etc. No confusion. Worth note- we were all college students and I think this helped keep us in line and on task.
We made sure to have a laid out program for the kids. Keeping a schedule helped keep things positive. We didn't know our kids and only had them briefly though.
Themes for each trip helped come up with ideas on what to focus on and kept the counselors interested. archeology, Arizona history, wilderness skills are three we had that come to mind