These are the same people you covered on Tuesday, the HPWREN project providing long-distance WiFi networking in the San Diego region. They apparently do line of sight links to the various mountain ridges and peaks in the air, then shoot down to rural areas like the Indian reservation.

The problem with the idea is that you only get extremely localized coverage at the endpoint. Then I guess maybe you put an antenna there and you run ethernet through a complex of buildings. But it's not like the whole reservation gets broadband this way, or the whole island. It's just one tiny spot, plus whatever you can hook up to it.