diff --git a/lib/Models/Catalog/CatalogItems/KmlCatalogItem.ts b/lib/Models/Catalog/CatalogItems/KmlCatalogItem.ts
index 63417b460b6..e8a58a4444c 100644
--- a/lib/Models/Catalog/CatalogItems/KmlCatalogItem.ts
+++ b/lib/Models/Catalog/CatalogItems/KmlCatalogItem.ts
@@ -1,25 +1,17 @@
 import i18next from "i18next";
 import { computed, makeObservable, override } from "mobx";
-import Cartesian3 from "terriajs-cesium/Source/Core/Cartesian3";
-import Cartographic from "terriajs-cesium/Source/Core/Cartographic";
-import Ellipsoid from "terriajs-cesium/Source/Core/Ellipsoid";
-import JulianDate from "terriajs-cesium/Source/Core/JulianDate";
-import PolygonHierarchy from "terriajs-cesium/Source/Core/PolygonHierarchy";
 import Resource from "terriajs-cesium/Source/Core/Resource";
-import sampleTerrain from "terriajs-cesium/Source/Core/sampleTerrain";
-import ConstantProperty from "terriajs-cesium/Source/DataSources/ConstantProperty";
 import KmlDataSource from "terriajs-cesium/Source/DataSources/KmlDataSource";
-import Property from "terriajs-cesium/Source/DataSources/Property";
+import TerriaError, { networkRequestError } from "../../../Core/TerriaError";
 import isDefined from "../../../Core/isDefined";
 import readXml from "../../../Core/readXml";
-import TerriaError, { networkRequestError } from "../../../Core/TerriaError";
 import CatalogMemberMixin from "../../../ModelMixins/CatalogMemberMixin";
 import MappableMixin from "../../../ModelMixins/MappableMixin";
 import UrlMixin from "../../../ModelMixins/UrlMixin";
 import KmlCatalogItemTraits from "../../../Traits/TraitsClasses/KmlCatalogItemTraits";
 import CreateModel from "../../Definition/CreateModel";
-import HasLocalData from "../../HasLocalData";
 import { ModelConstructorParameters } from "../../Definition/Model";
+import HasLocalData from "../../HasLocalData";
 import proxyCatalogItemUrl from "../proxyCatalogItemUrl";
 
 const kmzRegex = /\.kmz$/i;
@@ -62,45 +54,44 @@ class KmlCatalogItem
     return "1d";
   }
 
-  protected forceLoadMapItems(): Promise<void> {
-    return new Promise<string | Resource | Document | Blob>((resolve) => {
-      if (isDefined(this.kmlString)) {
-        const parser = new DOMParser();
-        resolve(parser.parseFromString(this.kmlString, "text/xml"));
-      } else if (isDefined(this._kmlFile)) {
-        if (this._kmlFile.name && this._kmlFile.name.match(kmzRegex)) {
-          resolve(this._kmlFile);
+  protected async forceLoadMapItems(): Promise<void> {
+    try {
+      const kmlLoadInput = await new Promise<
+        string | Resource | Document | Blob
+      >((resolve) => {
+        if (isDefined(this.kmlString)) {
+          const parser = new DOMParser();
+          resolve(parser.parseFromString(this.kmlString, "text/xml"));
+        } else if (isDefined(this._kmlFile)) {
+          if (this._kmlFile.name && this._kmlFile.name.match(kmzRegex)) {
+            resolve(this._kmlFile);
+          } else {
+            resolve(readXml(this._kmlFile));
+          }
+        } else if (isDefined(this.url)) {
+          resolve(proxyCatalogItemUrl(this, this.url));
         } else {
-          resolve(readXml(this._kmlFile));
+          throw networkRequestError({
+            sender: this,
+            title: i18next.t("models.kml.unableToLoadItemTitle"),
+            message: i18next.t("models.kml.unableToLoadItemMessage")
+          });
         }
-      } else if (isDefined(this.url)) {
-        resolve(proxyCatalogItemUrl(this, this.url));
-      } else {
-        throw networkRequestError({
+      });
+      this._dataSource = await KmlDataSource.load(kmlLoadInput, {
+        clampToGround: this.clampToGround
+      } as any);
+    } catch (e) {
+      throw networkRequestError(
+        TerriaError.from(e, {
           sender: this,
-          title: i18next.t("models.kml.unableToLoadItemTitle"),
-          message: i18next.t("models.kml.unableToLoadItemMessage")
-        });
-      }
-    })
-      .then((kmlLoadInput) => {
-        return KmlDataSource.load(kmlLoadInput);
-      })
-      .then((dataSource) => {
-        this._dataSource = dataSource;
-        this.doneLoading(dataSource); // Unsure if this is necessary
-      })
-      .catch((e) => {
-        throw networkRequestError(
-          TerriaError.from(e, {
-            sender: this,
-            title: i18next.t("models.kml.errorLoadingTitle"),
-            message: i18next.t("models.kml.errorLoadingMessage", {
-              appName: this.terria.appName
-            })
+          title: i18next.t("models.kml.errorLoadingTitle"),
+          message: i18next.t("models.kml.errorLoadingMessage", {
+            appName: this.terria.appName
           })
-        );
-      });
+        })
+      );
+    }
   }
 
   @computed
@@ -115,98 +106,6 @@ class KmlCatalogItem
   protected forceLoadMetadata(): Promise<void> {
     return Promise.resolve();
   }
-
-  private doneLoading(kmlDataSource: KmlDataSource) {
-    // Clamp features to terrain.
-    if (isDefined(this.terria.cesium) && this.clampPolygonsToGround) {
-      const positionsToSample: Cartographic[] = [];
-      const correspondingCartesians: Cartesian3[] = [];
-
-      const entities = kmlDataSource.entities.values;
-      for (let i = 0; i < entities.length; ++i) {
-        const entity = entities[i];
-
-        const polygon = entity.polygon;
-        if (isDefined(polygon)) {
-          polygon.perPositionHeight = true as unknown as Property;
-          const polygonHierarchy = getPropertyValue<PolygonHierarchy>(
-            polygon.hierarchy
-          );
-          if (polygonHierarchy) {
-            samplePolygonHierarchyPositions(
-              polygonHierarchy,
-              positionsToSample,
-              correspondingCartesians
-            );
-          }
-        }
-      }
-      const terrainProvider = this.terria.cesium.scene.globe.terrainProvider;
-      sampleTerrain(terrainProvider, 11, positionsToSample).then(function () {
-        for (let i = 0; i < positionsToSample.length; ++i) {
-          const position = positionsToSample[i];
-          if (!isDefined(position.height)) {
-            continue;
-          }
-
-          Ellipsoid.WGS84.cartographicToCartesian(
-            position,
-            correspondingCartesians[i]
-          );
-        }
-
-        // Force the polygons to be rebuilt.
-        for (let i = 0; i < entities.length; ++i) {
-          const polygon = entities[i].polygon;
-          if (!isDefined(polygon)) {
-            continue;
-          }
-
-          const existingHierarchy = getPropertyValue<PolygonHierarchy>(
-            polygon.hierarchy
-          );
-          if (existingHierarchy) {
-            polygon.hierarchy = new ConstantProperty(
-              new PolygonHierarchy(
-                existingHierarchy.positions,
-                existingHierarchy.holes
-              )
-            );
-          }
-        }
-      });
-    }
-  }
 }
 
 export default KmlCatalogItem;
-
-function getPropertyValue<T>(property: Property | undefined): T | undefined {
-  if (property === undefined) {
-    return undefined;
-  }
-  return property.getValue(JulianDate.now());
-}
-
-function samplePolygonHierarchyPositions(
-  polygonHierarchy: PolygonHierarchy,
-  positionsToSample: Cartographic[],
-  correspondingCartesians: Cartesian3[]
-) {
-  const positions = polygonHierarchy.positions;
-
-  for (let i = 0; i < positions.length; ++i) {
-    const position = positions[i];
-    correspondingCartesians.push(position);
-    positionsToSample.push(Ellipsoid.WGS84.cartesianToCartographic(position));
-  }
-
-  const holes = polygonHierarchy.holes;
-  for (let i = 0; i < holes.length; ++i) {
-    samplePolygonHierarchyPositions(
-      holes[i],
-      positionsToSample,
-      correspondingCartesians
-    );
-  }
-}
diff --git a/lib/Traits/TraitsClasses/KmlCatalogItemTraits.ts b/lib/Traits/TraitsClasses/KmlCatalogItemTraits.ts
index f41fb6624b4..858d1364ab1 100644
--- a/lib/Traits/TraitsClasses/KmlCatalogItemTraits.ts
+++ b/lib/Traits/TraitsClasses/KmlCatalogItemTraits.ts
@@ -22,7 +22,7 @@ export default class KmlCatalogItemTraits extends mixTraits(
     type: "boolean",
     name: "Clamp to Ground",
     description:
-      "Whether the polygon features in this KML should be clamped to the terrain surface."
+      "true if we want the geometry features (Polygons, LineStrings and LinearRings) clamped to the ground"
   })
-  clampPolygonsToGround: boolean = true;
+  clampToGround: boolean = true;
 }