The horse abuse we have all seen at Supai/Havasu Falls/Havasupai (but why didn't we report?? I'm as guilty as anyone else) has finally reached the ears of authorities. Four horses in horrible condition were removed from the reservation, and one man brought into Federal Court on felony animal abuse charges.
The horses are being cared for by the Coconino Humane Association. They'd like some donations which will go directly to the care of the horses, most of which have huge sores and are 200 or more pounds underweight. Their hooves have already been treated by a farrier. There's more info on this page, plus news articles and a TV news link. You'll see a number of familiar names on the donor list.
The tribe makes millions of dollars down there every year with their overpriced camping fees, etc., but this kind of abuse has been going on for decades. I saw it the first time I went there in 1999, but others have told me they saw it decades before that.