U.S. District Judge Miranda Du issued the temporary restraining order late Friday. She scheduled a hearing in Las Vegas on Thursday for both sides to present their arguments. She said halting the roundup in the meantime was warranted given the evidence she's seen so far, including video shot by Laura Leigh, president of Wild Horse Education.
"The public interest is served when actions are taken to prohibit inhumane treatment of wild horses," Du wrote.
Gordon Cowan, a Reno lawyer for the advocacy group, said Du's order makes it clear that protecting America's wild horses from inhumane conduct "represents significant public interest."
According to the group, the three-plus minute video that it presented to Du depicts BLM contractors using electric prods, or "hot shots," to jolt mustangs into moving through loading chutes.
"It's a hot-shot fest," said Leigh, who posted the footage on YouTube . "Over and over and over again, the horses are hot shot."
BLM spokeswoman Heather Emmons said Monday the agency would have no comment because the matter involves active litigation.
However, the agency said in an earlier statement on its website that electric prods were used in the roundup Nov. 30 as a last resort, and that their use was "within pre-established guidelines of the gather."
"The contractor had made many attempts to load the wild horses that day using voice commands, body position, sounds and flags, to no avail," the statement said. "Per procedures and to avoid human injury, electric prods were used as a last resort once other handling aids did not work."
Similar footage at a different Nevada roundup near the Utah line in summer 2011 prompted BLM Director Bob Abbey late that year to order additional training for roundup workers and contractors.
"Aggressive and rough handling of wild horses is not acceptable, and we are actively taking steps to ensure that such behavior is not repeated," Abbey said at the time.
Abbey also issued a report outlining a number of new safeguards. The report said animal welfare experts told BLM officials during an investigation of the incident that electrical prods should be used only as a last resort when human or animal safety is in jeopardy. They said the prods should never be used on a horse's head.
In addition to inhumane treatment, Leigh argues the BLM is violating the Free-Roaming Wild Horse and Burro Act by failing to prove there are too many horses in the area for the land to sustain without suffering ecological damage.
"It really does seem insane to have to fight for a humane-care standard with an agency tasked by Congress to manage animals humanely," Leigh said in a telephone interview Monday.
Leigh said she's been denied the access she'd like to have at the Owyhee roundup site but is able to capture some scenes with sophisticated cameras with telephoto lenses.
A photojournalist and writer for Horseback Magazine from Minden, Nev., she won a favorable ruling from the 9th Circuit U.S. Court of Appeals last year over a 2010 roundup where she said BLM denied her access in violation of the First Amendment.
The three-judge panel in San Francisco overturned a lower court ruling and sent the case back to a U.S. judge in Reno to determine if BLM restrictions on media access to roundups are constitutional. That case is pending.