This small Jeep CJ-like vehicle was built by AMC in the early 1960s for the Marine Corps to be airlifted by helicopters. It features an aluminum body and air-cooled aluminum V4 engine as well as 4-wheel independent suspension, very exotic by AMC standards:
I believe there's a father & son Mighty Mite build thread on here somewhere! Although it may have been Jeep Forum. They were in the California mountains.