From the article:
"Overall, 15,045 sheep and 35,721 cattle grazed on national forests in the Sierra in 2009, the agency said.

Total grazing fees last year came to $168,942
"

Good grief! All that negative impact, and all it brings in is enough to pay for one or two staff positions!

By the way, I suddenly got a case of giardia symptoms at the end of my 4-day PCT hike through the Stanislaus N.F. area last summer. And I drank all the water untreated. HOWEVER... I got the worst attack at the end of day 4 of the hike. And the worst cattle-grazed area of the hike was covered on day 3. (I got a positive ID of the bug two weeks later.)

And I cannot find anywhere that says one can get symptoms that quickly.

This site reports:
"How soon do the symptoms appear? The incubation period is usually 5-15 days, with an average of 7-10 days."

And most other sites report, as does Wikipedia, "Symptoms usually begin 1 to 2 weeks (average 7 days) after an individual becomes infected." Although elsewhere it says a study showed 6-15 days.

The county health person who contacted me in a followup quickly dismissed the situation as caused by the water on the hike. But the numbers don't add up. I am thinking it might have been from the family pets, or maybe from the daycare my daughter was attending. But who knows?