They plan to rally in Las Vegas on Thursday in a bid to draw Obama's attention to what they consider to be mismanagement of wild horses by the Bureau of Land Management, the federal agency charged with their care.
A second rally is planned for Saturday in Carson City.
Advocates have been growing increasingly vocal over the pace of gathers and their scale, with the recently completed Calico muster in northern Nevada removing around 1900 horses.
A moratorium on musters is being sought pending a review of long-term management strategies.
The Equine Welfare Alliance says 48 horses have died as a result of the Calico muster and 30 foals were aborted.
It predicts further deaths as the horses grow accustomed to a change in diet and cope with injuries arising from the muster.
Representatives Vicki Tobin and John Holland said the bureau argued the round-ups were for the welfare of the horses.
"They claim the horses are starving but the photos and footage tell a different story. They claim the few thousand horses remaining free-roaming are ruining the ranges but the Government Accountability Office reports reflect the millions of privately owned livestock being subsidised by tax payers are the cause of the range degradation," the pair said in a statement.
Protesters will gather in Las Vegas at 1.30pm at the Lloyd D. George Federal Courthouse, 333 S. Las Vegas Building.
The Carson City will see protesters gather in front of the Legislative Building on North Carson Street, US Highway 395.