diff --git a/packages/deck.gl-geotiff/src/cog-layer.ts b/packages/deck.gl-geotiff/src/cog-layer.ts
index 0980b51..1edf00e 100644
--- a/packages/deck.gl-geotiff/src/cog-layer.ts
+++ b/packages/deck.gl-geotiff/src/cog-layer.ts
@@ -235,11 +235,13 @@ export class COGLayer<
     const inverseReproject = (x: number, y: number) =>
       converter.inverse<[number, number]>([x, y], false);
 
-    const geographicBounds = getGeographicBounds(image, converter);
-    this.props.onGeoTIFFLoad?.(geotiff, {
-      projection: sourceProjection,
-      geographicBounds,
-    });
+    if (this.props.onGeoTIFFLoad) {
+      const geographicBounds = getGeographicBounds(image, converter);
+      this.props.onGeoTIFFLoad(geotiff, {
+        projection: sourceProjection,
+        geographicBounds,
+      });
+    }
 
     this.setState({
       metadata,
diff --git a/packages/deck.gl-geotiff/src/geotiff-layer.ts b/packages/deck.gl-geotiff/src/geotiff-layer.ts
index e1c47aa..25e27e3 100644
--- a/packages/deck.gl-geotiff/src/geotiff-layer.ts
+++ b/packages/deck.gl-geotiff/src/geotiff-layer.ts
@@ -4,9 +4,15 @@ import { RasterLayer } from "@developmentseed/deck.gl-raster";
 import type { ReprojectionFns } from "@developmentseed/raster-reproject";
 import type { BaseClient, GeoTIFF, Pool } from "geotiff";
 import { extractGeotiffReprojectors } from "./geotiff-reprojection.js";
-import { defaultPool, fetchGeoTIFF, loadRgbImage } from "./geotiff.js";
+import {
+  defaultPool,
+  fetchGeoTIFF,
+  getGeographicBounds,
+  loadRgbImage,
+} from "./geotiff.js";
 import type { GeoKeysParser, ProjectionInfo } from "./proj.js";
 import { epsgIoGeoKeyParser } from "./proj.js";
+import proj4 from "proj4";
 
 const DEFAULT_MAX_ERROR = 0.125;
 
@@ -65,7 +71,22 @@ export interface GeoTIFFLayerProps extends CompositeLayerProps {
    * @param   {GeoTIFF}  geotiff
    * @param   {ProjectionInfo}  projection
    */
-  onGeoTIFFLoad?: (geotiff: GeoTIFF, projection: ProjectionInfo) => void;
+  onGeoTIFFLoad?: (
+    geotiff: GeoTIFF,
+    options: {
+      projection: ProjectionInfo;
+      /**
+       * Bounds of the image in geographic coordinates (WGS84) [minLon, minLat,
+       * maxLon, maxLat]
+       */
+      geographicBounds: {
+        west: number;
+        south: number;
+        east: number;
+        north: number;
+      };
+    },
+  ) => void;
 }
 
 const defaultProps = {
@@ -122,11 +143,19 @@ export class GeoTIFFLayer extends CompositeLayer<GeoTIFFLayerProps> {
       );
     }
 
-    this.props.onGeoTIFFLoad?.(geotiff, sourceProjection);
+    const converter = proj4(sourceProjection.def, "EPSG:4326");
+
+    if (this.props.onGeoTIFFLoad) {
+      const geographicBounds = getGeographicBounds(image, converter);
+      this.props.onGeoTIFFLoad(geotiff, {
+        projection: sourceProjection,
+        geographicBounds,
+      });
+    }
 
     const reprojectionFns = await extractGeotiffReprojectors(
       geotiff,
-      this.props.geoKeysParser!,
+      sourceProjection.def,
     );
     const { texture, height, width } = await loadRgbImage(image, {
       pool: this.props.pool || defaultPool(),
diff --git a/packages/deck.gl-geotiff/src/geotiff-reprojection.ts b/packages/deck.gl-geotiff/src/geotiff-reprojection.ts
index 66c8192..2a9c308 100644
--- a/packages/deck.gl-geotiff/src/geotiff-reprojection.ts
+++ b/packages/deck.gl-geotiff/src/geotiff-reprojection.ts
@@ -9,7 +9,6 @@ import {
 import proj4 from "proj4";
 import type { PROJJSONDefinition } from "proj4/dist/lib/core";
 import type Projection from "proj4/dist/lib/Proj";
-import type { GeoKeysParser } from "./proj";
 
 export const OGC_84: PROJJSONDefinition = {
   $schema: "https://proj.org/schemas/v0.7/projjson.schema.json",
@@ -90,7 +89,7 @@ export const OGC_84: PROJJSONDefinition = {
 // TODO: return a RasterReprojector instance, given the IFD and tile of interest?
 export async function extractGeotiffReprojectors(
   tiff: GeoTIFF,
-  geoKeysParser: GeoKeysParser,
+  sourceProjection: string | PROJJSONDefinition,
   outputCrs: string | PROJJSONDefinition | Projection = OGC_84,
 ): Promise<ReprojectionFns> {
   const image = await tiff.getImage();
@@ -99,13 +98,7 @@ export async function extractGeotiffReprojectors(
   // Only the top-level IFD has geo keys, so we'll derive overviews from this
   const baseGeotransform = extractGeotransform(image);
 
-  const sourceProjection = await geoKeysParser(image.getGeoKeys());
-  if (sourceProjection === null) {
-    throw new Error(
-      "Could not determine source projection from GeoTIFF geo keys",
-    );
-  }
-  const converter = proj4(sourceProjection.def, outputCrs);
+  const converter = proj4(sourceProjection, outputCrs);
   const { forwardTransform, inverseTransform } =
     fromGeoTransform(baseGeotransform);