This is actually turning into a fact-based discussion. Good work in starting it Bob -- and everyone else for contributing.
Lucky: for the reasons Sierra Nevada outlined, your stats are too far off to be useful. One misunderstanding seems to be the reliance of ranger stations on stock and implying -- well, it's not clear what the point is.
Depending on needs and conditions, both ranger stations and trail crews can be resupplied either by stock or helicopter (or the ranger carrying stuff in). Most stations were built around 1970 and materials taken in by both horse and helicopter. Three ranger stations are now being built as replacement and both helicopter and stock are used (with feed brought in for the stock -- they're not grazing).
In Sequoia Kings, a helicopter is specifically recognized as a "minimum tool" -- along with stock -- that can be used to support trail crews, rangers or emergency operations. This recognizes that both methods have an impact and that circumstances may support the use of one over the other. For instance, use 10 head of stock and two packers for 3 days or two flights for a total of 45 minutes and two landings of less than 10 minutes? Which has less impact?
In actual practice, most ranger's gear is brought in by helicopter -- too much snow in June, usually. It's taken out by stock in October. There are no resupplies between going in and coming out -- it all comes in at once! For an approximately 100+ day season, my wife and I bring in about 1,300 lbs of food and gear. So there's garbage from the food containers and packaging, but not a whole lot. Much of it (knowing you want all the details!) is bulk -- like flour or rice. The occasional can of Confit du Conard and, OK. a darned good wine selection. Note to travelers: good wine weighs exactly the same as bad wine).
And once again, the critical difference in people feces vs. horse manure is where it goes -- close to or far away from water. Ranger stations have outhouses (the solar ones don't work well, though Yosemite still uses them, I think).
And as for my own, ummm, waste being "unaccounted for"! Well, good taste forbids -- but I know where it is, don't you worry your pretty little head 'bout that!
Lies, damn lies and statisticsAn interesting statistic, though is:
A 1,000 pound horse will defecate approximately four to thirteen times each day and produce approximately nine tons of manure per year. The 1,000 pound horse will produce, on the average, 37 pounds of feces and 2.4 gallons of urine daily, which totals about 50 pounds of raw waste per day in feces and urine combined.
http://www.extension.org/pages/Stall_Waste_Production_and_Management
Typically a ton of horse manure will contain 11pounds of N, 2 pounds of P, and 8 pounds of potassium (K).
There's about 7,000 use nights by stock (in 2008 in all of Sequoia Kings). So based on the above, that's about 350,000 lbs. of urine and manure deposited. Where does it go? What impact does it have? I can say that most human waste is farther than 100 feet. And, as everyone knows, Wag Bags are now required for people in the Whitney corridor.
Diapers have been suggested for stock and they are used in city parks and even required on, for instance, some watershed lands (San Francisco near Crystal Springs -- I think). But obviously that's impossible with the above tonnage.
But you're again missing the point. As noted before, it's not zero sum. Impact by one user group (hikers, say) does NOT somehow justify equal impact by another (stock). The idea is to reduce impact by BOTH.
As another side note, your figure for backcountry visitors in Yosemite seems extremely high. Their site is down right now, but the literature up to about 2000 reports under 100,000 use nights (!) so the number of actual overnight users would be less. It might have gone up somewhat, but I don't believe by that much. I'll check back with their site. That's a lot of backcountry use. (By contrast, Sequoia Kings in 2003 had 22,000 backcountry users and a little over 100,000 use nights).
Hmmm. Too much information.
g.
