diff --git a/R/get_elevation.R b/R/get_elevation.R
new file mode 100644
index 0000000..0a0f458
--- /dev/null
+++ b/R/get_elevation.R
@@ -0,0 +1,17 @@
+#' .. content for \description{} (no empty lines) ..
+#'
+#' .. content for \details{} ..
+#'
+#' @title
+#' @param 
+#' @return
+#' @author Whitney Bagge
+#' @export
+get_glw <- function() {
+  
+  url_cattle <- "https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/LHBICE#"
+  url_cattle_out <- GET(url_cattle)
+  unzipped_glw_cattle <- unzip(url_cattle_out)
+  Aw_layer <- if_else(str_detect(names(unzipped_glw_cattle), "Aw")==TRUE, )
+  
+}
\ No newline at end of file
diff --git a/R/get_glw.R b/R/get_glw.R
new file mode 100644
index 0000000..3357f24
--- /dev/null
+++ b/R/get_glw.R
@@ -0,0 +1,18 @@
+#' .. content for \description{} (no empty lines) ..
+#'
+#' .. content for \details{} ..
+#'
+#' @title
+#' @param 
+#' @return
+#' @author Whitney Bagge
+#' @export
+get_glw <- function() {
+
+  url_cattle <- "https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/LHBICE#"
+  #taxa cattle sheep goat have three urls here switch function (like if_else); have the three targets 
+  url_cattle_out <- GET(url_cattle)
+  unzipped_glw_cattle <- unzip(url_cattle_out)
+  Aw_layer <- if_else(str_detect(names(unzipped_glw_cattle), "Aw")==TRUE, )
+  
+}
diff --git a/R/get_grazingcap.R b/R/get_grazingcap.R
new file mode 100644
index 0000000..9e072c7
--- /dev/null
+++ b/R/get_grazingcap.R
@@ -0,0 +1,17 @@
+#' .. content for \description{} (no empty lines) ..
+#'
+#' .. content for \details{} ..
+#'
+#' @title
+#' @param 
+#' @return
+#' @author Whitney Bagge
+#' @export
+get_glw <- function() {
+  
+  url_cattle <- "https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/LHBICE#"
+  url_cattle_out <- GET(url_cattle)
+  unzipped_glw_cattle <- unzip(url_cattle_out)
+  Aw_layer <- if_else(str_detect(names(unzipped_glw_cattle), "Aw")==TRUE, )
+  
+}
diff --git a/R/preprocess_glw.R b/R/preprocess_glw.R
new file mode 100644
index 0000000..72fb446
--- /dev/null
+++ b/R/preprocess_glw.R
@@ -0,0 +1,16 @@
+#' .. content for \description{} (no empty lines) ..
+#'
+#' .. content for \details{} ..
+#'
+#' @title
+#' @param bounding_boxes
+#' @return
+#' @author Whitney Bagge
+#' @export
+preprocess_glw <- function(glw_layer, bounding_boxes) {
+  
+  extent_object <- extent(bounding_boxes)
+  glw_layer_out <- crop(glw_layer, extent_object)
+  return(glw_layer_out)
+  
+}
diff --git a/R/process_elevation.R b/R/process_elevation.R
new file mode 100644
index 0000000..6714755
--- /dev/null
+++ b/R/process_elevation.R
@@ -0,0 +1,17 @@
+#' .. content for \description{} (no empty lines) ..
+#'
+#' .. content for \details{} ..
+#'
+#' @title
+#' @param bounding_boxes
+#' @return
+#' @author Whitney Bagge
+#' @export
+process_elevation <- function(elevation_layer_raw, bounding_boxes) {
+  
+  extent_object <- extent(bounding_boxes)
+  elevation_layer_raw_out <- crop(elevation_layer_raw, extent_object)
+  
+  return(elevation_layer_raw_out)
+  
+}
diff --git a/R/process_grazingcap.R b/R/process_grazingcap.R
new file mode 100644
index 0000000..72fb446
--- /dev/null
+++ b/R/process_grazingcap.R
@@ -0,0 +1,16 @@
+#' .. content for \description{} (no empty lines) ..
+#'
+#' .. content for \details{} ..
+#'
+#' @title
+#' @param bounding_boxes
+#' @return
+#' @author Whitney Bagge
+#' @export
+preprocess_glw <- function(glw_layer, bounding_boxes) {
+  
+  extent_object <- extent(bounding_boxes)
+  glw_layer_out <- crop(glw_layer, extent_object)
+  return(glw_layer_out)
+  
+}
diff --git a/_targets.R b/_targets.R
index e6526ca..eed5ccc 100644
--- a/_targets.R
+++ b/_targets.R
@@ -113,7 +113,29 @@ source_targets <- tar_plan(
   },
   repository = "local", 
   format = "file"
-  )
+  ),
+  
+  ## GLW
+
+  tar_target(glw_cattle, get_glw()),
+  tar_target(glw_sheep, get_glw()),
+  tar_target(glw_goats, get_glw()),
+  tar_target(glw_cattle_preprocessed, preprocess_glw(glw_cattle, bounding_boxes)),
+  #need to cache
+  
+  ## ELEVATION
+  
+  tar_target(elevation_layer_raw, get_elevation()),
+  tar_target(elevation_layer_processed, 
+             process_elevation(elevation_layer_processed, bounding_boxes)),
+  #need to cache
+  
+  ## GRAZING CAPACITY
+  
+  tar_target(grazingcap_raw, get_grazingcap()),
+  tar_target(grazingcap_processed, 
+             process_grazingcap(grazingcap_layer_processed, bounding_boxes)),
+  #need to cache
   
 )