We obtained snow survey (depth) and snow pillow
data (snow water equivalent) from Government of British Columbia weather station data from various stations scattered throughout the study area (21-49 years of data; available at http://wlapwww.gov.bc.ca/rfc/river_fore cast/snowp.htm).
To estimate the snow's water-yield capacity, researchers weigh it, using a device called a snow pillow
that resembles a 10-foot-diameter waterbed filled with antifreeze.
In response, subalpine firs grow a thick mat of branches beneath the drifted snow pillows
. On some trees in exposed locales, the leeward thicket can extend 20 feet from the trunk of the tree.
The Central Sierra Snow Laboratory in Soda Springs, Calif., will be retiring 100 or so of its mechanical snow pillows
now used to measure the Sierra Nevada snowpack.