Thanks for the suggestions so far. Many of them contribute to preventing a situation where outside help would be needed. This seems the best approach to emergency situations -- don't get in them in the first place.

What I was looking for was suggestions in assembling a kit to provide to a support crew, who might be called upon to respond to a HELP request. If the hiking group incurs an injury, loses an important trip component, or happens upon a hiker in need of assistance, they might request external help. Those responding to a request for help would need to have a 'Rescue Kit' with them to deal with whatever issues they might encounter when they reach the group.

When the Scouts hiked at Philmont two years ago, there was a backup system in place. The Philmont Scout Ranch provides checkpoint camps throughout the facility, so a group was never more than a day from access to help. This might not be so in a place like Yosimite or Yellowstone.

I am expecting the Scouters to use the '911' function of SPOT to contact SAR if they have a life-threatening issue. What I am trying to assemble (with your assistance) is a gear package for responders to a HELP request. Then they can help with whatever happens on the trail that might be less than life threatening, but will require someone to be helped or taken off of the trail.

Thanks again for your input.