To the average person, the difference may seem negligible (both sides agree that the horses have been frolicking about footloose for decades), but the horses' freedom depends on whether or not Netherlands can persuade the federal government to recognize them as "wild."
Earlier this month, the Forest Service announced plans to round up the "feral" horses and auction them off.
Public outrage was fast and furious, so the Forest Service agreed to take another look at the plan.
Any acceptable solution, Netherlands says, takes into account the horses' unique souls.
"The true value of any living being is not dependent on the opinion we may have of it," she says. "Each individual life and the quality of it should be considered."
Along those lines, we'd like to introduce you to our top 10 herd members:
Champ is a lieutenant stallion, which means it's his job to keep watch over his band of horses 24/7 and protect them from intruders. He once saved another horse from drowning.
Missy was Champ's main mare. She made all the important decisions, such as which way to run away from danger, and where to look for food, water, and shelter. She died of old age this month. She was 22 years old.
Two-week-old Diamond, pictured with his mother, Sapphire, was born August 1. He was just learning how to walk when the Forest Service announced plans to round the horses up and auction them off. Had the government gone through with it, Netherlands says, "He would surely not have survived."
Half Tail, 12, is such a calm, patient stallion that he let one of the young horses in his band chew on his tail. She nibbled it in half.
The Bachelors. Just like human mothers, horse mothers don't want their sons hanging around mooching forever. After they get kicked out of their birth band, the young stallions run around with a bunch of other bachelors for a couple years until they get the urge to find a filly or two and settle down.
In his prime, Young Dillon (who's no longer young) was the lead stallion in his band. Now the mares are looking elsewhere so he's joined a group of bachelors and taken on a peacemaker role. Netherlands describes him as a "loyal friend."
Freckles is one of only three horses in the Salt River area with blue eyes. Bet you can guess where she got her name.
Quatro and a colt enjoy a dinner of eel grass in the Salt River. This behavior is not seen in any other herd in the country, Netherlands says.
Buffy, an elegant and playful 3-year-old filly, recently caught the eye of a stallion named GoPro. Netherlands reports: "She's totally in love."
Little Doc here is Clara's first foal. Looks like she's settling into this mom thing just fine.