These horses are from the White Mountain herd - Sweetwater County Wyoming.
As of August 2011 the BLM is planning to roundup and remove most of the horses from this and surrounding areas. A few will be returned but the mares will be given birth control drugs. Originally BLM was going to castrate all the stallions but this plan was thwarted by legal action in Washington DC. These horses live in vast deserts and they are often hard to find. Many more sheep and cattle are allowed to graze on federal land than horses.It appears that there will be very few foals in the future.