The animals were to be moved to short-term and long-term housing nationwide in response to depleted food supplies in the natural grazing areas, according to BLM.

The animal welfare organization In Defense of Animals -- whose attorneys alleges that the moving is traumatizing and sometimes fatal to horses -- says it plans to file a second lawsuit Dec. 1 seeking a permanent injunction against the gather.

If the permanent injunction fails, the BLM will proceed with the gather Dec. 28.