Manna by Kenneth P. Gurney

The Coca-cola can tossed from the passing station wagon
scuds across the pavement into the gravel shoulder
and stops in the grass near my hiking boots
where the continental divide trail emerges from the pines
to cross the two-lane state highway. 
The soda can fizzy-bleeds its dark brown liquid 
from a tiny puncture where the broken pop-top 
requires a real opening.
I bend my pack laden back to pick it up
so my Swiss army knife may ram through the aluminum
and I may quench a twelve mile thirst,
knowing I have ten miles to go before camp.