It's not the lack of pack animals responsible for some trails being abandoned, it's lack of trail crew people. That's caused by budget cuts. I don't know of a single trail that's been abandoned as a result of a lack of stock support. Once again: these rulings apply only to commercial outfitters, not administrative or private. No effect on trails. None.
And, sure, HSHA lists poop as a concern but their primary concern are the environmental impacts of stock and the fact that there's little or no regulation of those impacts. Let's move on from horse manure and how it's a manly part of the west. Camping next to a sewage treatment plant or a corral is not high on my list of backcountry experiences. Nor is seeing a meadow eaten down to a putting green.
Craig London, quoted in the original article, is one of the best low-impact outfitters around. But even a packer doing everything in as environmentally sensitive way as possible can still bring 20 1,200 pound animals into the wilderness. On, say, a 5 day trip, those animals will produce 3,500 lbs of manure and 240 gallons of urine. Much of the phosphates and nitrates from that waste will go into streams and lakes where they will provide nutrients for algae. In addition, one study in Yosemite found that 3 - 6% of the stock in the study carried giardia and cryptosporidium. So there's the potential of tens of thousands of cysts being washed into rivers and streams.
After a day's ride, the horses are released to graze and they often roll in the meadow to get the sweat off. Those "roll pits" can persist for years. In alpine meadows (above, say, 9,500 feet or so in the Sierra) I've seen pits take 30+ years to recover. And those animals will consume over 2,000 lbs of meadow grasses during that trip.
Now, all those impact are the result of supporting, say, 5 people on a wilderness trip. Can that be justified? If a scout group of 15 camped in a meadow, cut down swaths of grass and dug pits, they'd be given a citation -- certainly a Darned Serious Talk. But ALL of the impacts listed above are allowed and accepted when stock does it. Two different sets of rules guide the allowable impacts of people with stock and people on trips without stock.
Your examples on people leaving trash, washing in streams etc. are good, but you miss the point that those are illegal. It is perfectly legal for stock to create all of those same impacts. Rhapsodic peans to the glory of the noble critter do not address the damage they do to fragile alpine terrain.
I don't understand why you're upset with the people-caused impacts and not those of stock? I'm upset by both and think there's a lot that can be done to mitigate the latter.
And what all this really comes down to is is to what extent visitors -- whether on stock or foot only -- have a right to expect seeing an absolutely pristine meadow when they're traveling in Wilderness? The unfortunate reality is that there are few meadows along the length of the John Muir Trail that a user can camp at and see a meadow where grazing is not allowed and where the grasses and beldings and ducks etc. are allowed to go through their life cycle without the possible impacts of horses eating their habitat. As Randy Morgenson once put it:
All the meadows in Evolution Valley were grazed this summer, and they all looked it. Yet Franklin Meadow apparently was not, and in October it was a place of knee high grasses, ripe and open panicles drifting on the moving air, luminous-bronze in the backlight. It was a very different place and a very different emotional experience of a mountain meadow, and entirely consistent with what one might rightly expect of a national park backcountry. It was a garden. I sometimes wonder whether range management concepts are any more applicable to our business than timber management concepts. The difference between a grazed meadow and a logged forest may only be one of scale.
--Randy Morgenson, 1989 McClure Meadow end of season report
I think we all have a right to see such pristine meadows. That's the whole idea.
