By Gillian Ferris Kohl
http://stream.publicbroadcasting.net/production/mp3/knau/local-knau-974278.mp3
Flagstaff, AZ – For the last few weeks, many parts of northern Arizona have been gripped by what amounts to a pollen blizzard. The culprits are the Ponderosa pine trees. And, as Arizona Public Radio's Gillian Ferris Kohl reports, their annual pollination cycle is creating one dusty, yellow mess.