diff --git a/src/App.tsx b/src/App.tsx
index 5102663..4c52f0d 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -1,9 +1,5 @@
 import { useCallback, useMemo, useState, useReducer, ChangeEvent } from 'react';
-import {
-  MapMetadataResponseWithClientBand,
-  BandWithCmapValues,
-  SourceList,
-} from './types/maps';
+import { MapMetadataResponseWithClientBand, SourceList } from './types/maps';
 import { ColorMapControls } from './components/ColorMapControls';
 import { fetchProducts } from './utils/fetchUtils';
 import {
@@ -30,7 +26,7 @@ function App() {
   const [isAuthenticated, setIsAuthenticated] = useState<boolean | null>(null);
 
   /** query the bands to use as the baselayers of the map */
-  useQuery<BandWithCmapValues[] | undefined>({
+  useQuery<MapMetadataResponseWithClientBand[] | undefined>({
     initialData: undefined,
     queryKey: [isAuthenticated],
     queryFn: async () => {
@@ -38,33 +34,17 @@ function App() {
       // map baselayers
       const mapsMetadata = await fetchProducts('maps');
 
-      // Loop through each map's metadata and reduce the map's bands
-      // into a single array
-      const finalBands = mapsMetadata.reduce(
-        (
-          prev: BandWithCmapValues[],
-          curr: MapMetadataResponseWithClientBand
-        ) => {
-          if (curr.bands.length) {
-            return prev.concat(curr.bands);
-          } else {
-            return prev;
-          }
-        },
-        []
-      );
-
-      // If we end up with no bands for some reason, return early
-      if (!finalBands.length) return;
+      // // If we end up with no maps for some reason, return early
+      if (!mapsMetadata.length) return;
 
       // Set the baselayersState with the finalBands; note that this action will also set the
       // activeBaselayer to be finalBands[0]
       dispatchBaselayersChange({
         type: SET_BASELAYERS_STATE,
-        baselayers: finalBands,
+        baselayerMaps: mapsMetadata,
       });
 
-      return finalBands;
+      return mapsMetadata;
     },
   });
 
@@ -167,31 +147,29 @@ function App() {
     }
   }, [baselayersState.activeBaselayer]);
 
-  const { activeBaselayer, internalBaselayersState } = baselayersState;
+  const { activeBaselayer, internalBaselayerMaps } = baselayersState;
   return (
     <>
       <Login
         isAuthenticated={isAuthenticated}
         setIsAuthenticated={setIsAuthenticated}
       />
-      {isAuthenticated !== null &&
-        activeBaselayer &&
-        internalBaselayersState && (
-          <OpenLayersMap
-            baselayersState={baselayersState}
-            dispatchBaselayersChange={dispatchBaselayersChange}
-            sourceLists={sourceLists}
-            activeSourceListIds={activeSourceListIds}
-            onSelectedSourceListsChange={onSelectedSourceListsChange}
-            highlightBoxes={optimisticHighlightBoxes}
-            setBoxes={updateHighlightBoxes}
-            activeBoxIds={activeBoxIds}
-            setActiveBoxIds={setActiveBoxIds}
-            onSelectedHighlightBoxChange={onSelectedHighlightBoxChange}
-            submapData={submapData}
-            addOptimisticHighlightBox={addOptimisticHighlightBox}
-          />
-        )}
+      {isAuthenticated !== null && activeBaselayer && internalBaselayerMaps && (
+        <OpenLayersMap
+          baselayersState={baselayersState}
+          dispatchBaselayersChange={dispatchBaselayersChange}
+          sourceLists={sourceLists}
+          activeSourceListIds={activeSourceListIds}
+          onSelectedSourceListsChange={onSelectedSourceListsChange}
+          highlightBoxes={optimisticHighlightBoxes}
+          setBoxes={updateHighlightBoxes}
+          activeBoxIds={activeBoxIds}
+          setActiveBoxIds={setActiveBoxIds}
+          onSelectedHighlightBoxChange={onSelectedHighlightBoxChange}
+          submapData={submapData}
+          addOptimisticHighlightBox={addOptimisticHighlightBox}
+        />
+      )}
       {isAuthenticated !== null &&
         assertBand(activeBaselayer) &&
         activeBaselayer.cmap &&
diff --git a/src/components/BaselayerSections.tsx b/src/components/BaselayerSections.tsx
new file mode 100644
index 0000000..85cd78a
--- /dev/null
+++ b/src/components/BaselayerSections.tsx
@@ -0,0 +1,74 @@
+import { LayerSelectorProps } from './LayerSelector';
+import { CollapsibleSection } from './CollapsibleSection';
+import { makeLayerName } from '../utils/layerUtils';
+import { EXTERNAL_BASELAYERS } from '../configs/mapSettings';
+
+type BaselayerSectionsProps = {
+  internalBaselayerMaps: LayerSelectorProps['internalBaselayerMaps'];
+  activeBaselayerId: LayerSelectorProps['activeBaselayerId'];
+  isFlipped: LayerSelectorProps['isFlipped'];
+  onBaselayerChange: LayerSelectorProps['onBaselayerChange'];
+};
+
+export function BaselayerSections({
+  internalBaselayerMaps,
+  activeBaselayerId,
+  isFlipped,
+  onBaselayerChange,
+}: BaselayerSectionsProps) {
+  return (
+    <>
+      {internalBaselayerMaps?.map((map, index) => (
+        <CollapsibleSection summary={map.name} defaultOpen={index === 0}>
+          {map.bands.map((band) => (
+            <div className="input-container" key={band.map_id + '-' + band.id}>
+              <input
+                type="radio"
+                id={String(band.id)}
+                value={band.id}
+                name="baselayer"
+                checked={band.id === activeBaselayerId}
+                onChange={() =>
+                  onBaselayerChange(
+                    String(band.id),
+                    String(band.map_id),
+                    'layerMenu'
+                  )
+                }
+              />
+              <label htmlFor={String(band.id)}>{makeLayerName(band)}</label>
+            </div>
+          ))}
+        </CollapsibleSection>
+      ))}
+      {
+        <CollapsibleSection summary="Comparison maps" defaultOpen={true}>
+          {EXTERNAL_BASELAYERS.map((bl) => (
+            <div
+              className={`input-container ${bl.disabledState(isFlipped) ? 'disabled' : ''}`}
+              key={bl.id}
+              title={
+                bl.disabledState(isFlipped)
+                  ? 'The current RA range is incompatible with this baselayer.'
+                  : undefined
+              }
+            >
+              <input
+                type="radio"
+                id={bl.id}
+                value={bl.id}
+                name="baselayer"
+                checked={bl.id === activeBaselayerId}
+                onChange={() =>
+                  onBaselayerChange(bl.id, undefined, 'layerMenu')
+                }
+                disabled={bl.disabledState(isFlipped)}
+              />
+              <label htmlFor={bl.id}>{bl.name}</label>
+            </div>
+          ))}
+        </CollapsibleSection>
+      }
+    </>
+  );
+}
diff --git a/src/components/CollapsibleSection.tsx b/src/components/CollapsibleSection.tsx
new file mode 100644
index 0000000..0f89857
--- /dev/null
+++ b/src/components/CollapsibleSection.tsx
@@ -0,0 +1,16 @@
+import { ReactNode } from 'react';
+
+type Props = {
+  summary: ReactNode;
+  children: ReactNode;
+  defaultOpen: boolean;
+};
+
+export function CollapsibleSection({ summary, defaultOpen, children }: Props) {
+  return (
+    <details open={defaultOpen}>
+      <summary>{summary}</summary>
+      {children}
+    </details>
+  );
+}
diff --git a/src/components/LayerSelector.tsx b/src/components/LayerSelector.tsx
index a492bc8..ca10d00 100644
--- a/src/components/LayerSelector.tsx
+++ b/src/components/LayerSelector.tsx
@@ -1,18 +1,17 @@
 import { MouseEvent, useCallback, useEffect, useRef, useState } from 'react';
-import { BandWithCmapValues, SourceList } from '../types/maps';
-import { makeLayerName } from '../utils/layerUtils';
+import { MapMetadataResponseWithClientBand, SourceList } from '../types/maps';
 import { LayersIcon } from './icons/LayersIcon';
 import './styles/layer-selector.css';
 import { MapProps } from './OpenLayersMap';
-import { EXTERNAL_BASELAYERS } from '../configs/mapSettings';
 import {
   BaselayerHistoryNavigation,
   BaselayerHistoryNavigationProps,
 } from './BaselayerHistoryNavigation';
 import { LockClosedIcon } from './icons/LockClosedIcon';
 import { LockOpenIcon } from './icons/LockOpenIcon';
+import { BaselayerSections } from './BaselayerSections';
 
-interface Props
+export interface LayerSelectorProps
   extends Omit<
     MapProps & BaselayerHistoryNavigationProps,
     | 'baselayersState'
@@ -24,17 +23,18 @@ interface Props
   > {
   onBaselayerChange: (
     selectedBaselayerId: string,
+    selectedMapId: string | undefined,
     context: 'layerMenu' | 'goBack' | 'goForward',
     flipped?: boolean
   ) => void;
   activeBaselayerId?: number | string;
   sourceLists: SourceList[];
   isFlipped: boolean;
-  internalBaselayers: BandWithCmapValues[] | undefined;
+  internalBaselayerMaps: MapMetadataResponseWithClientBand[] | undefined;
 }
 
 export function LayerSelector({
-  internalBaselayers,
+  internalBaselayerMaps,
   onBaselayerChange,
   activeBaselayerId,
   sourceLists,
@@ -48,7 +48,7 @@ export function LayerSelector({
   disableGoForward,
   goBack,
   goForward,
-}: Props) {
+}: LayerSelectorProps) {
   const menuRef = useRef<HTMLDivElement | null>(null);
   const [lockMenu, setLockMenu] = useState(false);
   const previousLockMenuHandlerRef = useRef<(e: KeyboardEvent) => void>(null);
@@ -133,41 +133,12 @@ export function LayerSelector({
         </div>
         <fieldset>
           <legend>Baselayers</legend>
-          {internalBaselayers?.map((band) => (
-            <div className="input-container" key={band.map_id + '-' + band.id}>
-              <input
-                type="radio"
-                id={String(band.id)}
-                value={band.id}
-                name="baselayer"
-                checked={band.id === activeBaselayerId}
-                onChange={(e) => onBaselayerChange(e.target.value, 'layerMenu')}
-              />
-              <label htmlFor={String(band.id)}>{makeLayerName(band)}</label>
-            </div>
-          ))}
-          {EXTERNAL_BASELAYERS.map((bl) => (
-            <div
-              className={`input-container ${bl.disabledState(isFlipped) ? 'disabled' : ''}`}
-              key={bl.id}
-              title={
-                bl.disabledState(isFlipped)
-                  ? 'The current RA range is incompatible with this baselayer.'
-                  : undefined
-              }
-            >
-              <input
-                type="radio"
-                id={bl.id}
-                value={bl.id}
-                name="baselayer"
-                checked={bl.id === activeBaselayerId}
-                onChange={(e) => onBaselayerChange(e.target.value, 'layerMenu')}
-                disabled={bl.disabledState(isFlipped)}
-              />
-              <label htmlFor={bl.id}>{bl.name}</label>
-            </div>
-          ))}
+          <BaselayerSections
+            internalBaselayerMaps={internalBaselayerMaps}
+            activeBaselayerId={activeBaselayerId}
+            isFlipped={isFlipped}
+            onBaselayerChange={onBaselayerChange}
+          />
         </fieldset>
         {sourceLists.length ? (
           <fieldset>
diff --git a/src/components/OpenLayersMap.tsx b/src/components/OpenLayersMap.tsx
index fff7747..e23579c 100644
--- a/src/components/OpenLayersMap.tsx
+++ b/src/components/OpenLayersMap.tsx
@@ -17,7 +17,14 @@ import VectorSource from 'ol/source/Vector';
 import { Point } from 'ol/geom';
 import { Circle as CircleStyle, Style, Fill, Stroke } from 'ol/style';
 import 'ol/ol.css';
-import { BaselayersState, Box, SourceList, SubmapData } from '../types/maps';
+import {
+  BandWithCmapValues,
+  BaselayersState,
+  Box,
+  ExternalBaselayer,
+  SourceList,
+  SubmapData,
+} from '../types/maps';
 import {
   DEFAULT_INTERNAL_MAP_SETTINGS,
   EXTERNAL_BASELAYERS,
@@ -88,13 +95,13 @@ export function OpenLayersMap({
   const [flipTiles, setFlipTiles] = useState(true);
 
   const [backHistoryStack, setBackHistoryStack] = useState<
-    { id: string; flipped: boolean }[]
+    { id: string; mapId: string | undefined; flipped: boolean }[]
   >([]);
   const [forwardHistoryStack, setForwardHistoryStack] = useState<
-    { id: string; flipped: boolean }[]
+    { id: string; mapId: string | undefined; flipped: boolean }[]
   >([]);
 
-  const { activeBaselayer, internalBaselayersState } = baselayersState;
+  const { activeBaselayer, internalBaselayerMaps } = baselayersState;
 
   /**
    * Handler fires when user changes map layers. If the units of the new
@@ -106,6 +113,7 @@ export function OpenLayersMap({
   const onBaselayerChange = useCallback(
     (
       selectedBaselayerId: string,
+      selectedBaselayerMapId: string | undefined,
       context: 'layerMenu' | 'goBack' | 'goForward',
       flipped?: boolean
     ) => {
@@ -113,11 +121,24 @@ export function OpenLayersMap({
 
       const { activeBaselayer } = baselayersState;
 
-      const newActiveBaselayer = isExternalBaselayer
-        ? EXTERNAL_BASELAYERS.find((b) => b.id === selectedBaselayerId)
-        : baselayersState.internalBaselayersState?.find(
-            (b) => b.id === Number(selectedBaselayerId)
-          );
+      let newActiveBaselayer:
+        | ExternalBaselayer
+        | BandWithCmapValues
+        | undefined = undefined;
+
+      if (isExternalBaselayer) {
+        newActiveBaselayer = EXTERNAL_BASELAYERS.find(
+          (b) => b.id === selectedBaselayerId
+        );
+      } else {
+        const map = baselayersState.internalBaselayerMaps?.find(
+          (map) => map.id === Number(selectedBaselayerMapId)
+        );
+        newActiveBaselayer = map?.bands.find(
+          (b) => b.id === Number(selectedBaselayerId)
+        );
+      }
+
       if (!newActiveBaselayer) return;
 
       if (context === 'goBack') {
@@ -125,6 +146,10 @@ export function OpenLayersMap({
         setForwardHistoryStack((prev) =>
           [...prev].concat({
             id: String(activeBaselayer?.id),
+            mapId:
+              activeBaselayer && 'map_id' in activeBaselayer
+                ? String(activeBaselayer.map_id)
+                : undefined,
             flipped: flipTiles,
           })
         );
@@ -132,6 +157,10 @@ export function OpenLayersMap({
         setBackHistoryStack((prev) =>
           [...prev].concat({
             id: String(activeBaselayer?.id),
+            mapId:
+              activeBaselayer && 'map_id' in activeBaselayer
+                ? String(activeBaselayer.map_id)
+                : undefined,
             flipped: flipTiles,
           })
         );
@@ -140,6 +169,10 @@ export function OpenLayersMap({
         setBackHistoryStack((prev) =>
           [...prev].concat({
             id: String(activeBaselayer?.id),
+            mapId:
+              activeBaselayer && 'map_id' in activeBaselayer
+                ? String(activeBaselayer.map_id)
+                : undefined,
             flipped: flipTiles,
           })
         );
@@ -156,7 +189,7 @@ export function OpenLayersMap({
       });
     },
     [
-      baselayersState.internalBaselayersState,
+      baselayersState.internalBaselayerMaps,
       baselayersState.activeBaselayer,
       backHistoryStack,
       flipTiles,
@@ -166,37 +199,55 @@ export function OpenLayersMap({
 
   const goBack = useCallback(() => {
     const baselayer = backHistoryStack[backHistoryStack.length - 1];
-    onBaselayerChange(baselayer.id, 'goBack', baselayer.flipped);
+    onBaselayerChange(
+      baselayer.id,
+      baselayer.mapId,
+      'goBack',
+      baselayer.flipped
+    );
   }, [onBaselayerChange, backHistoryStack]);
 
   const goForward = useCallback(() => {
     const baselayer = forwardHistoryStack[forwardHistoryStack.length - 1];
-    onBaselayerChange(baselayer.id, 'goForward', baselayer.flipped);
+    onBaselayerChange(
+      baselayer.id,
+      baselayer.mapId,
+      'goForward',
+      baselayer.flipped
+    );
   }, [onBaselayerChange, forwardHistoryStack]);
 
   const tileLayers = useMemo(() => {
-    return internalBaselayersState?.map((band) => {
-      return new TileLayer({
-        properties: { id: 'baselayer-' + band.id },
-        source: new XYZ({
-          url: `${SERVICE_URL}/maps/${band.map_id}/${band.id}/{z}/{-y}/{x}/tile.png?cmap=${band.cmap}&vmin=${band.cmapValues.min}&vmax=${band.cmapValues.max}&flip=${flipTiles}`,
-          tileGrid: new TileGrid({
-            extent: [-180, -90, 180, 90],
-            origin: [-180, 90],
-            tileSize: band.tile_size,
-            resolutions: getBaselayerResolutions(
-              180,
-              band.tile_size,
-              band.levels - 1
-            ),
-          }),
-          interpolate: false,
-          projection: 'EPSG:4326',
-          tilePixelRatio: band.tile_size / 256,
-        }),
+    const tempTileLayers: TileLayer<XYZ>[] = [];
+
+    internalBaselayerMaps?.forEach((map) => {
+      map.bands.forEach((band) => {
+        tempTileLayers.push(
+          new TileLayer({
+            properties: { id: 'baselayer-' + band.id },
+            source: new XYZ({
+              url: `${SERVICE_URL}/maps/${band.map_id}/${band.id}/{z}/{-y}/{x}/tile.png?cmap=${band.cmap}&vmin=${band.cmapValues.min}&vmax=${band.cmapValues.max}&flip=${flipTiles}`,
+              tileGrid: new TileGrid({
+                extent: [-180, -90, 180, 90],
+                origin: [-180, 90],
+                tileSize: band.tile_size,
+                resolutions: getBaselayerResolutions(
+                  180,
+                  band.tile_size,
+                  band.levels - 1
+                ),
+              }),
+              interpolate: false,
+              projection: 'EPSG:4326',
+              tilePixelRatio: band.tile_size / 256,
+            }),
+          })
+        );
       });
     });
-  }, [internalBaselayersState, flipTiles]);
+
+    return tempTileLayers;
+  }, [internalBaselayerMaps, flipTiles]);
 
   const externalTileLayers = useMemo(() => {
     return EXTERNAL_BASELAYERS.map((b) => {
@@ -522,7 +573,7 @@ export function OpenLayersMap({
         flipped={flipTiles}
       />
       <LayerSelector
-        internalBaselayers={internalBaselayersState}
+        internalBaselayerMaps={internalBaselayerMaps}
         onBaselayerChange={onBaselayerChange}
         activeBaselayerId={activeBaselayer?.id}
         sourceLists={sourceLists}
diff --git a/src/components/styles/layer-selector.css b/src/components/styles/layer-selector.css
index 5929285..7484f44 100644
--- a/src/components/styles/layer-selector.css
+++ b/src/components/styles/layer-selector.css
@@ -62,8 +62,15 @@
 
 .input-container {
   display: flex;
-  column-gap: 0.5em;
-  font-size: 0.9em;
+  align-items: center;
+  column-gap: 0.75em;
+  font-size: 0.75em;
+  margin: 1px;
+}
+
+.input-container > input {
+  margin: 0;
+  font-size: 0.5;
 }
 
 .layers-icon {
diff --git a/src/configs/mapSettings.ts b/src/configs/mapSettings.ts
index c723acb..a07dddf 100644
--- a/src/configs/mapSettings.ts
+++ b/src/configs/mapSettings.ts
@@ -22,29 +22,29 @@ export const DEFAULT_INTERNAL_MAP_SETTINGS = {
 
 export const EXTERNAL_BASELAYERS: ExternalBaselayer[] = [
   {
-    id: 'external-unwise-neo4',
-    name: 'Legacy Survey | unWISE neo4',
+    id: 'external-unwise-neo6',
+    name: 'Legacy Survey | unWISE neo6',
     projection: 'EPSG:3857',
-    url: 'https://imagine.legacysurvey.org/static/tiles/unwise-neo4/1/{z}/{x}/{y}.jpg',
+    url: 'https://s3.us-west-2.amazonaws.com/unwise-neo6.legacysurvey.org/{z}/{x}/{y}.jpg',
     extent: transformExtent(
       [-180, -MERCATOR_MAX_LAT, 180, MERCATOR_MAX_LAT],
       'EPSG:4326',
       'EPSG:3857'
     ),
-    maxZoom: 8,
+    maxZoom: 10,
     disabledState: (isFlipped: boolean) => !isFlipped,
   },
   {
-    id: 'external-unwise-neo6',
-    name: 'Legacy Survey | unWISE neo6',
+    id: 'external-unwise-neo4',
+    name: 'Legacy Survey | unWISE neo4',
     projection: 'EPSG:3857',
-    url: 'https://s3.us-west-2.amazonaws.com/unwise-neo6.legacysurvey.org/{z}/{x}/{y}.jpg',
+    url: 'https://imagine.legacysurvey.org/static/tiles/unwise-neo4/1/{z}/{x}/{y}.jpg',
     extent: transformExtent(
       [-180, -MERCATOR_MAX_LAT, 180, MERCATOR_MAX_LAT],
       'EPSG:4326',
       'EPSG:3857'
     ),
-    maxZoom: 10,
+    maxZoom: 8,
     disabledState: (isFlipped: boolean) => !isFlipped,
   },
 ];
diff --git a/src/index.css b/src/index.css
index 642f79e..d26a5b5 100644
--- a/src/index.css
+++ b/src/index.css
@@ -151,3 +151,7 @@ body {
   background-color: #921925 !important;
   color: white !important;
 }
+
+summary {
+  cursor: default;
+}
diff --git a/src/reducers/baselayersReducer.ts b/src/reducers/baselayersReducer.ts
index 916f911..863acd6 100644
--- a/src/reducers/baselayersReducer.ts
+++ b/src/reducers/baselayersReducer.ts
@@ -2,6 +2,7 @@ import {
   BandWithCmapValues,
   BaselayersState,
   ExternalBaselayer,
+  MapMetadataResponseWithClientBand,
 } from '../types/maps';
 
 export function assertExternalBaselayer(
@@ -18,7 +19,7 @@ export function assertBand(
 
 export const initialBaselayersState: BaselayersState = {
   activeBaselayer: undefined,
-  internalBaselayersState: undefined,
+  internalBaselayerMaps: undefined,
 };
 
 export const CHANGE_CMAP_TYPE = 'CHANGE_CMAP';
@@ -48,7 +49,7 @@ type ChangeBaselayerAction = {
 
 type SetBaselayersAction = {
   type: typeof SET_BASELAYERS_STATE;
-  baselayers: BandWithCmapValues[];
+  baselayerMaps: MapMetadataResponseWithClientBand[];
 };
 
 export type Action =
@@ -61,8 +62,8 @@ export function baselayersReducer(state: BaselayersState, action: Action) {
   switch (action.type) {
     case 'SET_BASELAYERS_STATE': {
       return {
-        internalBaselayersState: action.baselayers,
-        activeBaselayer: action.baselayers[0],
+        internalBaselayerMaps: action.baselayerMaps,
+        activeBaselayer: action.baselayerMaps[0].bands[0],
       };
     }
     case 'CHANGE_CMAP': {
@@ -72,9 +73,21 @@ export function baselayersReducer(state: BaselayersState, action: Action) {
           cmap: action.cmap,
         };
         return {
-          internalBaselayersState: state.internalBaselayersState?.map((b) =>
-            b.id === action.activeBaselayer.id ? activeBaselayer : b
-          ),
+          internalBaselayerMaps: state.internalBaselayerMaps?.map((map) => {
+            if (
+              'map_id' in action.activeBaselayer &&
+              map.id === action.activeBaselayer.map_id
+            ) {
+              return {
+                ...map,
+                bands: map.bands.map((b) =>
+                  b.id === action.activeBaselayer.id ? activeBaselayer : b
+                ),
+              };
+            } else {
+              return map;
+            }
+          }),
           activeBaselayer,
         };
       } else {
@@ -95,9 +108,21 @@ export function baselayersReducer(state: BaselayersState, action: Action) {
           },
         };
         return {
-          internalBaselayersState: state.internalBaselayersState?.map((b) =>
-            b.id === action.activeBaselayer.id ? activeBaselayer : b
-          ),
+          internalBaselayerMaps: state.internalBaselayerMaps?.map((map) => {
+            if (
+              'map_id' in action.activeBaselayer &&
+              map.id === action.activeBaselayer.map_id
+            ) {
+              return {
+                ...map,
+                bands: map.bands.map((b) =>
+                  b.id === action.activeBaselayer.id ? activeBaselayer : b
+                ),
+              };
+            } else {
+              return map;
+            }
+          }),
           activeBaselayer,
         };
       } else {
diff --git a/src/types/maps.ts b/src/types/maps.ts
index dc2134b..05dc539 100644
--- a/src/types/maps.ts
+++ b/src/types/maps.ts
@@ -121,8 +121,8 @@ export type ExternalBaselayer = {
 export type BaselayersState = {
   /** the active baselayer selected in the map's legend */
   activeBaselayer?: BandWithCmapValues | ExternalBaselayer;
-  /** the bands used as internal baselayers */
-  internalBaselayersState?: BandWithCmapValues[];
+  /** the internal maps whose bands are used as internal baselayers */
+  internalBaselayerMaps?: MapMetadataResponseWithClientBand[];
 };
 
 export type SubmapData = {