diff --git a/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.cpp b/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.cpp
index 1feb014e02..5d62d42e5e 100644
--- a/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.cpp
+++ b/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.cpp
@@ -139,7 +139,20 @@ void RigFemPartResultsCollection::setActiveFormationNames( RigFormationNames* ac
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-RigFormationNames* RigFemPartResultsCollection::activeFormationNames()
+std::vector<QString> RigFemPartResultsCollection::formationNames() const
+{
+    if ( activeFormationNames() )
+    {
+        return activeFormationNames()->formationNames();
+    }
+
+    return {};
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+const RigFormationNames* RigFemPartResultsCollection::activeFormationNames() const
 {
     return m_activeFormationNamesData.p();
 }
@@ -2037,7 +2050,7 @@ RigFemScalarResultFrames* RigFemPartResultsCollection::calculateFormationIndices
     float  inf      = std::numeric_limits<float>::infinity();
     dstFrameData.resize( valCount, inf );
 
-    RigFormationNames* activeFormNames = m_activeFormationNamesData.p();
+    const RigFormationNames* activeFormNames = m_activeFormationNamesData.p();
 
     frameCountProgress.incrementProgress();
 
diff --git a/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.h b/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.h
index eb068b56d7..7594c957b7 100644
--- a/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.h
+++ b/ApplicationCode/GeoMech/GeoMechDataModel/RigFemPartResultsCollection.h
@@ -55,8 +55,8 @@ public:
                                  const RigFemPartCollection* femPartCollection );
     ~RigFemPartResultsCollection() override;
 
-    void               setActiveFormationNames( RigFormationNames* activeFormationNames );
-    RigFormationNames* activeFormationNames();
+    void                 setActiveFormationNames( RigFormationNames* activeFormationNames );
+    std::vector<QString> formationNames() const;
 
     void                             addElementPropertyFiles( const std::vector<QString>& filenames );
     std::vector<RigFemResultAddress> removeElementPropertyFiles( const std::vector<QString>& filenames );
@@ -157,12 +157,14 @@ private:
     RigFemScalarResultFrames* calculateGamma( int partIndex, const RigFemResultAddress& resVarAddr );
     RigFemScalarResultFrames* calculateFormationIndices( int partIndex, const RigFemResultAddress& resVarAddr );
 
+    const RigFormationNames* activeFormationNames() const;
+
 private:
     cvf::Collection<RigFemPartResults>  m_femPartResults;
     cvf::ref<RifGeoMechReaderInterface> m_readerInterface;
     cvf::ref<RifElementPropertyReader>  m_elementPropertyReader;
     cvf::cref<RigFemPartCollection>     m_femParts;
-    cvf::ref<RigFormationNames>         m_activeFormationNamesData;
+    cvf::cref<RigFormationNames>        m_activeFormationNamesData;
 
     double m_cohesion;
     double m_frictionAngleRad;
diff --git a/ApplicationCode/ProjectDataModel/GridCrossPlots/RimGridCrossPlotDataSet.cpp b/ApplicationCode/ProjectDataModel/GridCrossPlots/RimGridCrossPlotDataSet.cpp
index e5428224d8..e4896e2e4c 100644
--- a/ApplicationCode/ProjectDataModel/GridCrossPlots/RimGridCrossPlotDataSet.cpp
+++ b/ApplicationCode/ProjectDataModel/GridCrossPlots/RimGridCrossPlotDataSet.cpp
@@ -1001,15 +1001,11 @@ void RimGridCrossPlotDataSet::updateLegendRange()
                 RimEclipseCase* eclipseCase = dynamic_cast<RimEclipseCase*>( m_case() );
                 if ( eclipseCase )
                 {
-                    RigFormationNames* formationNames = eclipseCase->eclipseCaseData()->activeFormationNames();
-                    if ( formationNames )
+                    const std::vector<QString> categoryNames = eclipseCase->eclipseCaseData()->formationNames();
+                    if ( !categoryNames.empty() )
                     {
-                        const std::vector<QString>& categoryNames = formationNames->formationNames();
-                        if ( !categoryNames.empty() )
-                        {
-                            legendConfig()->setNamedCategoriesInverse( categoryNames );
-                            legendConfig()->setAutomaticRanges( 0, categoryNames.size() - 1, 0, categoryNames.size() - 1 );
-                        }
+                        legendConfig()->setNamedCategoriesInverse( categoryNames );
+                        legendConfig()->setAutomaticRanges( 0, categoryNames.size() - 1, 0, categoryNames.size() - 1 );
                     }
                 }
             }
diff --git a/ApplicationCode/ProjectDataModel/RimEclipsePropertyFilter.cpp b/ApplicationCode/ProjectDataModel/RimEclipsePropertyFilter.cpp
index 534fa64667..a36a1d309f 100644
--- a/ApplicationCode/ProjectDataModel/RimEclipsePropertyFilter.cpp
+++ b/ApplicationCode/ProjectDataModel/RimEclipsePropertyFilter.cpp
@@ -403,15 +403,10 @@ void RimEclipsePropertyFilter::computeResultValueRange()
                     if ( m_resultDefinition->resultType() == RiaDefines::FORMATION_NAMES )
                     {
                         CVF_ASSERT( parentContainer()->reservoirView()->eclipseCase()->eclipseCaseData() );
-                        CVF_ASSERT(
-                            parentContainer()->reservoirView()->eclipseCase()->eclipseCaseData()->activeFormationNames() );
 
-                        const std::vector<QString>& fnVector = parentContainer()
-                                                                   ->reservoirView()
-                                                                   ->eclipseCase()
-                                                                   ->eclipseCaseData()
-                                                                   ->activeFormationNames()
-                                                                   ->formationNames();
+                        const std::vector<QString> fnVector =
+                            parentContainer()->reservoirView()->eclipseCase()->eclipseCaseData()->formationNames();
+
                         setCategoryNames( fnVector );
                     }
                     else if ( m_resultDefinition->resultVariable() == RiaDefines::completionTypeResultName() )
diff --git a/ApplicationCode/ProjectDataModel/RimEclipseResultDefinition.cpp b/ApplicationCode/ProjectDataModel/RimEclipseResultDefinition.cpp
index 4b3cb02b47..4969d09acf 100644
--- a/ApplicationCode/ProjectDataModel/RimEclipseResultDefinition.cpp
+++ b/ApplicationCode/ProjectDataModel/RimEclipseResultDefinition.cpp
@@ -1882,15 +1882,15 @@ void RimEclipseResultDefinition::updateRangesForExplicitLegends( RimRegularLegen
             {
                 if ( this->resultType() == RiaDefines::FORMATION_NAMES )
                 {
-                    const std::vector<QString>& fnVector = eclipseCaseData->activeFormationNames()->formationNames();
+                    std::vector<QString> fnVector = eclipseCaseData->formationNames();
                     legendConfigToUpdate->setNamedCategoriesInverse( fnVector );
                 }
                 else if ( this->resultType() == RiaDefines::ALLEN_DIAGRAMS )
                 {
                     if ( this->resultVariable() == RiaDefines::formationAllenResultName() )
                     {
-                        const std::vector<QString>& fnVector = eclipseCaseData->activeFormationNames()->formationNames();
-                        std::vector<int>            fnameIdxes;
+                        const std::vector<QString> fnVector = eclipseCaseData->formationNames();
+                        std::vector<int>           fnameIdxes;
                         for ( int i = static_cast<int>( fnVector.size() ); i > 0; --i )
                             fnameIdxes.push_back( i - 1 );
 
diff --git a/ApplicationCode/ProjectDataModel/RimEclipseView.cpp b/ApplicationCode/ProjectDataModel/RimEclipseView.cpp
index 3d986b77d2..c7284bb3b0 100644
--- a/ApplicationCode/ProjectDataModel/RimEclipseView.cpp
+++ b/ApplicationCode/ProjectDataModel/RimEclipseView.cpp
@@ -1252,7 +1252,7 @@ void RimEclipseView::onUpdateLegends()
                     }
                     else
                     {
-                        const std::vector<QString>& fnVector = eclipseCase->activeFormationNames()->formationNames();
+                        const std::vector<QString> fnVector = eclipseCase->formationNames();
                         cellEdgeResult()->legendConfig()->setNamedCategoriesInverse( fnVector );
                     }
                 }
diff --git a/ApplicationCode/ProjectDataModel/RimGeoMechPropertyFilter.cpp b/ApplicationCode/ProjectDataModel/RimGeoMechPropertyFilter.cpp
index b93e795391..1a6c4bd04a 100644
--- a/ApplicationCode/ProjectDataModel/RimGeoMechPropertyFilter.cpp
+++ b/ApplicationCode/ProjectDataModel/RimGeoMechPropertyFilter.cpp
@@ -269,11 +269,7 @@ void RimGeoMechPropertyFilter::computeResultValueRange()
     {
         if ( resultDefinition->hasCategoryResult() )
         {
-            std::vector<QString> fnVector;
-            if ( resultDefinition->ownerCaseData()->femPartResults()->activeFormationNames() )
-            {
-                fnVector = resultDefinition->ownerCaseData()->femPartResults()->activeFormationNames()->formationNames();
-            }
+            std::vector<QString> fnVector = resultDefinition->ownerCaseData()->femPartResults()->formationNames();
             setCategoryNames( fnVector );
         }
         else
diff --git a/ApplicationCode/ProjectDataModel/RimGeoMechResultDefinition.cpp b/ApplicationCode/ProjectDataModel/RimGeoMechResultDefinition.cpp
index 18465609f3..d1dafb0f27 100644
--- a/ApplicationCode/ProjectDataModel/RimGeoMechResultDefinition.cpp
+++ b/ApplicationCode/ProjectDataModel/RimGeoMechResultDefinition.cpp
@@ -697,11 +697,7 @@ void RimGeoMechResultDefinition::updateLegendTextAndRanges( RimRegularLegendConf
 
     if ( this->hasCategoryResult() )
     {
-        std::vector<QString> fnVector;
-        if ( gmCase->femPartResults()->activeFormationNames() )
-        {
-            fnVector = gmCase->femPartResults()->activeFormationNames()->formationNames();
-        }
+        std::vector<QString> fnVector = gmCase->femPartResults()->formationNames();
         legendConfigToUpdate->setNamedCategoriesInverse( fnVector );
     }
 
diff --git a/ApplicationCode/ProjectDataModel/RimWellLogTrack.cpp b/ApplicationCode/ProjectDataModel/RimWellLogTrack.cpp
index 6cbdfd742a..154cb4ef43 100644
--- a/ApplicationCode/ProjectDataModel/RimWellLogTrack.cpp
+++ b/ApplicationCode/ProjectDataModel/RimWellLogTrack.cpp
@@ -2027,17 +2027,11 @@ std::vector<QString> RimWellLogTrack::formationNamesVector( RimCase* rimCase )
 
     if ( eclipseCase )
     {
-        if ( eclipseCase->eclipseCaseData()->activeFormationNames() )
-        {
-            return eclipseCase->eclipseCaseData()->activeFormationNames()->formationNames();
-        }
+        return eclipseCase->eclipseCaseData()->formationNames();
     }
     else if ( geoMechCase )
     {
-        if ( geoMechCase->geoMechData()->femPartResults()->activeFormationNames() )
-        {
-            return geoMechCase->geoMechData()->femPartResults()->activeFormationNames()->formationNames();
-        }
+        return geoMechCase->geoMechData()->femPartResults()->formationNames();
     }
 
     return std::vector<QString>();
diff --git a/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.cpp b/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.cpp
index 884b0d1997..bb7c7d02af 100644
--- a/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.cpp
+++ b/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.cpp
@@ -2890,7 +2890,7 @@ void RigCaseCellResultsData::setActiveFormationNames( RigFormationNames* activeF
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-RigFormationNames* RigCaseCellResultsData::activeFormationNames()
+const RigFormationNames* RigCaseCellResultsData::activeFormationNames() const
 {
     return m_activeFormationNamesData.p();
 }
diff --git a/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.h b/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.h
index e5d1b7c656..f65f8051a9 100644
--- a/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.h
+++ b/ApplicationCode/ReservoirDataModel/RigCaseCellResultsData.h
@@ -58,7 +58,7 @@ public:
     const RifReaderInterface* readerInterface() const;
     void                      setHdf5Filename( const QString& hdf5SourSimFilename );
     void                      setActiveFormationNames( RigFormationNames* activeFormationNames );
-    RigFormationNames*        activeFormationNames();
+    const RigFormationNames*  activeFormationNames() const;
     RigAllenDiagramData*      allenDiagramData();
 
     void                     setMainGrid( RigMainGrid* ownerGrid );
@@ -197,7 +197,7 @@ private:
 
 private:
     cvf::ref<RifReaderInterface>  m_readerInterface;
-    cvf::ref<RigFormationNames>   m_activeFormationNamesData;
+    cvf::cref<RigFormationNames>  m_activeFormationNamesData;
     cvf::ref<RigAllenDiagramData> m_allenDiagramData;
 
     std::vector<std::vector<std::vector<double>>>
diff --git a/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.cpp b/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.cpp
index d2ba7c58b0..545fd831f5 100644
--- a/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.cpp
+++ b/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.cpp
@@ -727,7 +727,7 @@ void RigEclipseCaseData::setActiveFormationNamesAndUpdatePlots( RigFormationName
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-RigFormationNames* RigEclipseCaseData::activeFormationNames()
+const RigFormationNames* RigEclipseCaseData::activeFormationNames() const
 {
     return m_matrixModelResults->activeFormationNames();
 }
@@ -735,7 +735,20 @@ RigFormationNames* RigEclipseCaseData::activeFormationNames()
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-RigAllenDiagramData* RigEclipseCaseData::allenDiagramData() 
+const std::vector<QString> RigEclipseCaseData::formationNames() const
+{
+    if ( activeFormationNames() )
+    {
+        return activeFormationNames()->formationNames();
+    }
+
+    return {};
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+RigAllenDiagramData* RigEclipseCaseData::allenDiagramData()
 {
     return m_matrixModelResults->allenDiagramData();
 }
diff --git a/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.h b/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.h
index 6c448a0607..826c3bc70a 100644
--- a/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.h
+++ b/ApplicationCode/ReservoirDataModel/RigEclipseCaseData.h
@@ -89,10 +89,11 @@ public:
 
     bool hasFractureResults() const;
 
-    void                 setActiveFormationNames( RigFormationNames* activeFormationNames );
-    void                 setActiveFormationNamesAndUpdatePlots( RigFormationNames* activeFormationNames );
-    RigFormationNames*   activeFormationNames();
-    RigAllenDiagramData* allenDiagramData();
+    void                       setActiveFormationNames( RigFormationNames* activeFormationNames );
+    void                       setActiveFormationNamesAndUpdatePlots( RigFormationNames* activeFormationNames );
+    const RigFormationNames*   activeFormationNames() const;
+    const std::vector<QString> formationNames() const;
+    RigAllenDiagramData*       allenDiagramData();
 
     void                                   setSimWellData( const cvf::Collection<RigSimWellData>& data );
     const cvf::Collection<RigSimWellData>& wellResults() const
diff --git a/ApplicationCode/ReservoirDataModel/RigEclipseCrossPlotDataExtractor.cpp b/ApplicationCode/ReservoirDataModel/RigEclipseCrossPlotDataExtractor.cpp
index 48fd526add..20a05e497a 100644
--- a/ApplicationCode/ReservoirDataModel/RigEclipseCrossPlotDataExtractor.cpp
+++ b/ApplicationCode/ReservoirDataModel/RigEclipseCrossPlotDataExtractor.cpp
@@ -47,8 +47,6 @@ RigEclipseCrossPlotResult
     RigCaseCellResultsData* resultData = caseData->results( RiaDefines::MATRIX_MODEL );
     if ( !resultData ) return result;
 
-    RigFormationNames* activeFormationNames = resultData->activeFormationNames();
-
     const std::vector<std::vector<double>>* catValuesForAllSteps = nullptr;
 
     if ( xAddress.isValid() && yAddress.isValid() )
@@ -136,6 +134,8 @@ RigEclipseCrossPlotResult
                 }
                 else if ( groupingType == GROUP_BY_FORMATION )
                 {
+                    const RigFormationNames* activeFormationNames = resultData->activeFormationNames();
+
                     if ( activeFormationNames )
                     {
                         int    category = 0;
diff --git a/ApplicationCode/ReservoirDataModel/RigFormationNames.h b/ApplicationCode/ReservoirDataModel/RigFormationNames.h
index c2341523e1..a6507fca73 100644
--- a/ApplicationCode/ReservoirDataModel/RigFormationNames.h
+++ b/ApplicationCode/ReservoirDataModel/RigFormationNames.h
@@ -29,7 +29,7 @@ public:
     RigFormationNames();
     ~RigFormationNames() override;
 
-    int formationIndexFromKLayerIdx( size_t Kidx )
+    int formationIndexFromKLayerIdx( size_t Kidx ) const
     {
         if ( Kidx >= m_nameIndexPrKLayer.size() ) return -1;
         return m_nameIndexPrKLayer[Kidx];
diff --git a/ApplicationCode/UserInterface/RiuResultTextBuilder.cpp b/ApplicationCode/UserInterface/RiuResultTextBuilder.cpp
index c50fa4b0d1..c1fd4f88dd 100644
--- a/ApplicationCode/UserInterface/RiuResultTextBuilder.cpp
+++ b/ApplicationCode/UserInterface/RiuResultTextBuilder.cpp
@@ -490,16 +490,15 @@ QString RiuResultTextBuilder::nncResultText()
                                 eclipseCase->allenDiagramData()->formationIndexCombinationFromCategory(
                                     ( *nncValues )[m_nncIndex] );
 
-                            RigFormationNames* fmNames = eclipseCase->activeFormationNames();
+                            std::vector<QString> fmNames = eclipseCase->formationNames();
                             // clang-format off
-                            if ( fmNames && 
-                                 fmIndexPair.first >= 0 && 
+                            if ( fmIndexPair.first >= 0 && 
                                  fmIndexPair.second >= 0 &&
-                                 fmNames->formationNames().size() > fmIndexPair.first &&
-                                 fmNames->formationNames().size() > fmIndexPair.second )
+                                 fmNames.size() > fmIndexPair.first &&
+                                 fmNames.size() > fmIndexPair.second )
                             {
-                                resultValueText = fmNames->formationNames()[fmIndexPair.first] + " - " +
-                                                  fmNames->formationNames()[fmIndexPair.second];
+                                resultValueText = fmNames[fmIndexPair.first] + " - " +
+                                                  fmNames[fmIndexPair.second];
                             }
                             // clang-format on
                         }