Beyond orienteering, I think the sport of rogaining would appeal to many here. Not sure how popular it is in the US, but there are bound to be some events people could try - start with a 3-6 hour event and work up to 24 hours. It's addictive.
It's similar to orienteering but team-based, everyone leaves en masse, and control points can be reached in any order within a fixed amount of time. This means you can be competitive by walking and relying on compass smarts rather than having to be able to run for hours on end.
I got into it a year or two ago here in Australia and have now competed in a state and national event plus others. Entered into the world champs in July, though we will be aiming mostly to not come last!
It's similar to orienteering but team-based, everyone leaves en masse, and control points can be reached in any order within a fixed amount of time. This means you can be competitive by walking and relying on compass smarts rather than having to be able to run for hours on end.
This looks like a calendar of US rogaining events: http://www.us.orienteering.org/orienteers/rogaines/events
I got into it a year or two ago here in Australia and have now competed in a state and national event plus others. Entered into the world champs in July, though we will be aiming mostly to not come last!