[R-sig-Geo] Coordinate system specification

[Ray Danner]

Dear community,

I would like to calculate average values from a few hundred raster
files and then query values for 217 specific points.  The raster files
are of evapotranspiration data in California
(http://goes.casil.ucdavis.edu/cimis/).  The maps have 2km resolution.
 I'm able to download the .asc files, visualize them, average them,
and query point values, but can't get the maps into the proper
coordinate system so that I can query points based on decimal degrees.
 The website states that the maps are in Albert's Equal Area
projection (http://goes.casil.ucdavis.edu/), though doesn't provide
any reference points (not sure if these are necessary).  Would anyone
be willing to point me in the correct direction regarding coordinate
systems?  Please see example below.

Thanks in advance.
Ray

#download: http://goes.casil.ucdavis.edu/cimis/2011/01/04/mc_et0_avg.asc.gz
library("maptools")
library("raster")
grid <- readAsciiGrid("/Users/rdanner/Downloads/mc_et0_avg.asc")
table <- data.frame(grid)
image(grid)
ETo<-raster(grid)
plot(ETo) #Note that the scale is not decimal degrees