[R-sig-Geo] how to draw borders

[Felipe Carrillo]

Hi:
Could someone show me how to add state borders to a shapefile.
Please follow the bellow link to download it.Thanks

http://docs.google.com/leaf?id=0B9LuhHLxsabgNmUxM2VhZmQtNzNlNC00ZDhiLTg0MTQtODJhN2U5MWI3ZTdi&hl=en&authkey=CMeh644K
http://docs.google.com/leaf?id=0B9LuhHLxsabgZTJkNmY3NmYtZjI3NS00ZmZlLTljMWEtZTkzOWY5NWJiNzZm&hl=en&authkey=CNHh6vkL
http://docs.google.com/leaf?id=0B9LuhHLxsabgYjIxZTAxZGYtYTc1Zi00M2Y0LWI2NDMtNTQwMzc2ODZjZTlm&hl=en&authkey=CPGYi9gL
http://docs.google.com/leaf?id=0B9LuhHLxsabgMDgyMTBjMjMtOGZjZS00OGM1LTgzNDQtMGM3M2JlYWNhMzky&hl=en&authkey=COWjorMD
http://docs.google.com/leaf?id=0B9LuhHLxsabgN2E4YTllOTEtMjhmMC00ZjY5LWFmYWQtMmQ0YmRmMzJjYWM5&hl=en&authkey=COWkixM
http://docs.google.com/leaf?id=0B9LuhHLxsabgODVkMmJlNjctYTQxZi00MDA5LWIzMDEtZDc0YTY4YjExMjc2&hl=en&authkey=CIzq0_EH
 
library(rgdal)
library(maptools)
dsn="C:/pathtoshapefile"
wolves.map <- readOGR(dsn=dsn, layer="PNW_wolf_habitat_grid")
cols<-heat.colors(16);cols
spplot(wolves.map, "PRED_SUIT", names.attr = "PRED_SUIT", col.regions=rev(cols),
    colorkey=list(space="bottom"), main = "Wolf Presence", as.table = TRUE)



Felipe D. Carrillo
Supervisory Fishery Biologist
Department of the Interior
US Fish & Wildlife Service
California, USA