diff --git a/NAMESPACE b/NAMESPACE
index 59bd8ca..6f9e87d 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -19,6 +19,7 @@ export(cumPoolsCreateAGB)
 export(cumPoolsSmooth)
 export(distMatch)
 export(extractToRast)
+export(gcLocatorCreate)
 export(gcidsCreate)
 export(m3ToBiomPlots)
 export(nmfac)
diff --git a/R/Boudewyn_cumPoolsCreate.R b/R/Boudewyn_cumPoolsCreate.R
index d0101f9..5206151 100644
--- a/R/Boudewyn_cumPoolsCreate.R
+++ b/R/Boudewyn_cumPoolsCreate.R
@@ -1,14 +1,14 @@
 #' Create `cumPools` data.table
 #'
-#' @param fullSpecies DESCRIPTION NEEDED
-#' @param gcMeta DESCRIPTION NEEDED
-#' @param userGcM3 DESCRIPTION NEEDED
-#' @param stable3 DESCRIPTION NEEDED
-#' @param stable4 DESCRIPTION NEEDED
-#' @param stable5 DESCRIPTION NEEDED
-#' @param stable6 DESCRIPTION NEEDED
-#' @param stable7 DESCRIPTION NEEDED
-#' @param thisAdmin DESCRIPTION NEEDED
+#' @param fullSpecies Species names found in study area.
+#' @param gcMeta Growth curve metadata table that links species with additional attributes.
+#' @param userGcM3 Growth curve metadata table that links species with additional attributes.
+#' @param stable3 Boudewyn table 3 subset to study area attributes.
+#' @param stable4 Boudewyn table 3 subset to study area attributes.
+#' @param stable5 Boudewyn table 3 subset to study area attributes.
+#' @param stable6 Boudewyn table 3 subset to study area attributes.
+#' @param stable7 Boudewyn table 3 subset to study area attributes.
+#' @param thisAdmin Study area metadata
 #'
 #' @return `cumPools` data.table
 #'
diff --git a/R/CBM-tools_gcLocatorCreate.R b/R/CBM-tools_gcLocatorCreate.R
new file mode 100644
index 0000000..0307d8a
--- /dev/null
+++ b/R/CBM-tools_gcLocatorCreate.R
@@ -0,0 +1,43 @@
+#' Create gcLocator raster layer
+#'
+#' Builds the gcLocator raster from site productivity, spatial unit, and leading species matched to
+#' a growth curve lookup table
+#'
+#' @param siteProductivity Productivity class raster layer
+#' @param spuRaster spatial unit ID raster layer
+#' @param leadSpecies leading species raster layer
+#' @param gcidLookup Table with metadata for each gcid
+#'
+#'
+#' @return `gcLocator` SpatRaster
+#'
+#' @export
+#' @importFrom data.table data.table as.data.table
+#' @importFrom terra rast
+gcLocatorCreate <- function(siteProductivity, spuRaster, leadSpecies, gcidLookup) {
+
+  #check if all rasters share the same CRS
+  if (!length(unique(lapply(list(siteProductivity, spuRaster, leadSpecies), crs))) == 1){
+    stop("Rasters do not all share the same CRS.")
+  }
+
+  #build gcTable from the raster layers
+  combine <- c(leadSpecies, spuRaster, siteProductivity)
+  gcTable <- as.data.table(combine, na.rm = FALSE)
+  setnames(gcTable, c("speciesID", "spatialunit", "prodclass"))
+  gcTable[, cell := 1:.N]
+
+  #merge gcTable with gcidLookup to get growth curve information for each pixel
+  gcTable <- merge(gcTable, gcidLookup, by = c("speciesId", "spatialunit", "prodclass"), all.x = TRUE)
+  colstokeep <- c("cell", "growthcurveid")
+  gcTable <- gcTable[, ..colstokeep]
+  setnames(gcTable, c("cell", "growthcurveid"))
+
+  #build the gcLocator raster layer
+  gcLocator <- rast(leadSpecies)
+  values(gcLocator) <- NA
+  values(gcLocator)[gcTable$cell] <- gcTable$growthcurveid
+
+  return(gcLocator)
+
+}
diff --git a/man/cumPoolsCreate.Rd b/man/cumPoolsCreate.Rd
index c9d969a..d7c0b70 100644
--- a/man/cumPoolsCreate.Rd
+++ b/man/cumPoolsCreate.Rd
@@ -17,23 +17,23 @@ cumPoolsCreate(
 )
 }
 \arguments{
-\item{fullSpecies}{DESCRIPTION NEEDED}
+\item{fullSpecies}{Species names found in study area.}
 
-\item{gcMeta}{DESCRIPTION NEEDED}
+\item{gcMeta}{Growth curve metadata table that links species with additional attributes.}
 
-\item{userGcM3}{DESCRIPTION NEEDED}
+\item{userGcM3}{Growth curve metadata table that links species with additional attributes.}
 
-\item{stable3}{DESCRIPTION NEEDED}
+\item{stable3}{Boudewyn table 3 subset to study area attributes.}
 
-\item{stable4}{DESCRIPTION NEEDED}
+\item{stable4}{Boudewyn table 3 subset to study area attributes.}
 
-\item{stable5}{DESCRIPTION NEEDED}
+\item{stable5}{Boudewyn table 3 subset to study area attributes.}
 
-\item{stable6}{DESCRIPTION NEEDED}
+\item{stable6}{Boudewyn table 3 subset to study area attributes.}
 
-\item{stable7}{DESCRIPTION NEEDED}
+\item{stable7}{Boudewyn table 3 subset to study area attributes.}
 
-\item{thisAdmin}{DESCRIPTION NEEDED}
+\item{thisAdmin}{Study area metadata}
 }
 \value{
 \code{cumPools} data.table
diff --git a/man/gcLocatorCreate.Rd b/man/gcLocatorCreate.Rd
new file mode 100644
index 0000000..0803379
--- /dev/null
+++ b/man/gcLocatorCreate.Rd
@@ -0,0 +1,24 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/CBM-tools_gcLocatorCreate.R
+\name{gcLocatorCreate}
+\alias{gcLocatorCreate}
+\title{Create gcLocator raster layer}
+\usage{
+gcLocatorCreate(siteProductivity, spuRaster, leadSpecies, gcidLookup)
+}
+\arguments{
+\item{siteProductivity}{Productivity class raster layer}
+
+\item{spuRaster}{spatial unit ID raster layer}
+
+\item{leadSpecies}{leading species raster layer}
+
+\item{gcidLookup}{Table with metadata for each gcid}
+}
+\value{
+\code{gcLocator} SpatRaster
+}
+\description{
+Builds the gcLocator raster from site productivity, spatial unit, and leading species matched to
+a growth curve lookup table
+}