diff --git a/MapControl/Shared/Etrs89UtmProjection.cs b/MapControl/Shared/Etrs89UtmProjection.cs
index 44673444..757105a8 100644
--- a/MapControl/Shared/Etrs89UtmProjection.cs
+++ b/MapControl/Shared/Etrs89UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// ETRS89 UTM Projection with zone number.
+    /// ETRS89 Universal Transverse Mercator Projection.
     /// </summary>
     public class Etrs89UtmProjection : TransverseMercatorProjection
     {
diff --git a/MapControl/Shared/MapProjectionFactory.cs b/MapControl/Shared/MapProjectionFactory.cs
index 260fbeb4..e021947e 100644
--- a/MapControl/Shared/MapProjectionFactory.cs
+++ b/MapControl/Shared/MapProjectionFactory.cs
@@ -33,7 +33,7 @@ namespace MapControl
                     break;
 
                 case Wgs84AutoUtmProjection.DefaultCrsId:
-                    projection = new Wgs84AutoUtmProjection();
+                    projection = new Wgs84AutoUtmProjection("");
                     break;
 
                 case Wgs84AutoTmProjection.DefaultCrsId:
diff --git a/MapControl/Shared/Nad27UtmProjection.cs b/MapControl/Shared/Nad27UtmProjection.cs
index c061189e..8c14514c 100644
--- a/MapControl/Shared/Nad27UtmProjection.cs
+++ b/MapControl/Shared/Nad27UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// NAD27 UTM Projection with zone number.
+    /// NAD27 Universal Transverse Mercator Projection.
     /// </summary>
     public class Nad27UtmProjection : TransverseMercatorProjection
     {
diff --git a/MapControl/Shared/Nad83UtmProjection.cs b/MapControl/Shared/Nad83UtmProjection.cs
index 207dcc58..0686d6ba 100644
--- a/MapControl/Shared/Nad83UtmProjection.cs
+++ b/MapControl/Shared/Nad83UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// NAD83 UTM Projection with zone number.
+    /// NAD83 Universal Transverse Mercator Projection.
     /// </summary>
     public class Nad83UtmProjection : TransverseMercatorProjection
     {
diff --git a/MapControl/Shared/TransverseMercatorProjection.cs b/MapControl/Shared/TransverseMercatorProjection.cs
index 9af93a34..eff98aad 100644
--- a/MapControl/Shared/TransverseMercatorProjection.cs
+++ b/MapControl/Shared/TransverseMercatorProjection.cs
@@ -9,7 +9,8 @@ namespace MapControl
 {
     /// <summary>
     /// Transverse Mercator Projection.
-    /// See https://en.wikipedia.org/wiki/Transverse_Mercator_projection.
+    /// See https://en.wikipedia.org/wiki/Transverse_Mercator_projection
+    /// and https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system.
     /// </summary>
     public class TransverseMercatorProjection : MapProjection
     {
diff --git a/MapControl/Shared/Wgs84AutoUtmProjection.cs b/MapControl/Shared/Wgs84AutoUtmProjection.cs
new file mode 100644
index 00000000..1fadc803
--- /dev/null
+++ b/MapControl/Shared/Wgs84AutoUtmProjection.cs
@@ -0,0 +1,61 @@
+using System;
+
+namespace MapControl
+{
+    /// <summary>
+    /// WGS84 Universal Transverse Mercator Projection with
+    /// automatic zone selection from projection center.
+    /// </summary>
+    public class Wgs84AutoUtmProjection : Wgs84UtmProjection
+    {
+        public const string DefaultCrsId = "AUTO2:42001";
+
+        private readonly string autoCrsId;
+
+        public Wgs84AutoUtmProjection()
+            : this(DefaultCrsId)
+        {
+            // XAML needs parameterless constructor
+        }
+
+        /// <summary>
+        /// When the crsId parameter is null or empty, the projection will use EPSG:32***.
+        /// </summary>
+        public Wgs84AutoUtmProjection(string crsId)
+            : base(31, true)
+        {
+            autoCrsId = crsId;
+
+            if (!string.IsNullOrEmpty(autoCrsId))
+            {
+                CrsId = autoCrsId;
+            }
+        }
+
+        public override Location Center
+        {
+            get => base.Center;
+            protected internal set
+            {
+                if (!base.Center.Equals(value))
+                {
+                    base.Center = value;
+
+                    var lon = Location.NormalizeLongitude(value.Longitude);
+                    var zone = (int)Math.Floor(lon / 6d) + 31;
+                    var north = value.Latitude >= 0d;
+
+                    if (Zone != zone || IsNorth != north)
+                    {
+                        SetZone(zone, north);
+
+                        if (!string.IsNullOrEmpty(autoCrsId))
+                        {
+                            CrsId = autoCrsId;
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/MapControl/Shared/Wgs84UtmProjection.cs b/MapControl/Shared/Wgs84UtmProjection.cs
index db6c8e92..5d909c28 100644
--- a/MapControl/Shared/Wgs84UtmProjection.cs
+++ b/MapControl/Shared/Wgs84UtmProjection.cs
@@ -3,8 +3,7 @@
 namespace MapControl
 {
     /// <summary>
-    /// WGS84 UTM Projection with zone number and north/south flag.
-    /// See https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system.
+    /// WGS84 Universal Transverse Mercator Projection.
     /// </summary>
     public class Wgs84UtmProjection : TransverseMercatorProjection
     {
@@ -42,47 +41,4 @@ namespace MapControl
             FalseNorthing = north ? 0d : 1e7;
         }
     }
-
-    /// <summary>
-    /// WGS84 UTM Projection with automatic zone selection from projection center.
-    /// </summary>
-    public class Wgs84AutoUtmProjection : Wgs84UtmProjection
-    {
-        public const string DefaultCrsId = "AUTO2:42001";
-
-        public Wgs84AutoUtmProjection()
-            : this(DefaultCrsId)
-        {
-            // XAML needs parameterless constructor
-        }
-
-        public Wgs84AutoUtmProjection(string crsId)
-            : base(31, true)
-        {
-            CrsId = crsId;
-        }
-
-        public override Location Center
-        {
-            get => base.Center;
-            protected internal set
-            {
-                if (!base.Center.Equals(value))
-                {
-                    base.Center = value;
-
-                    var lon = Location.NormalizeLongitude(value.Longitude);
-                    var zone = (int)Math.Floor(lon / 6d) + 31;
-                    var north = value.Latitude >= 0d;
-
-                    if (Zone != zone || IsNorth != north)
-                    {
-                        var crsId = CrsId;
-                        SetZone(zone, north);
-                        CrsId = crsId;
-                    }
-                }
-            }
-        }
-    }
 }
diff --git a/MapProjections/Shared/Ed50UtmProjection.cs b/MapProjections/Shared/Ed50UtmProjection.cs
index 473698f2..18ab4b18 100644
--- a/MapProjections/Shared/Ed50UtmProjection.cs
+++ b/MapProjections/Shared/Ed50UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl.Projections
 {
     /// <summary>
-    /// ED50 UTM Projection with zone number.
+    /// ED50 Universal Transverse Mercator Projection.
     /// </summary>
     public class Ed50UtmProjection : GeoApiProjection
     {
diff --git a/MapProjections/Shared/Etrs89UtmProjection.cs b/MapProjections/Shared/Etrs89UtmProjection.cs
index 9e251e0b..9043dd9f 100644
--- a/MapProjections/Shared/Etrs89UtmProjection.cs
+++ b/MapProjections/Shared/Etrs89UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl.Projections
 {
     /// <summary>
-    /// ETRS89 UTM Projection with zone number.
+    /// ETRS89 Universal Transverse Mercator Projection.
     /// </summary>
     public class Etrs89UtmProjection : GeoApiProjection
     {
diff --git a/MapProjections/Shared/Nad27UtmProjection.cs b/MapProjections/Shared/Nad27UtmProjection.cs
index 6fd217c4..891474ea 100644
--- a/MapProjections/Shared/Nad27UtmProjection.cs
+++ b/MapProjections/Shared/Nad27UtmProjection.cs
@@ -3,8 +3,7 @@
 namespace MapControl.Projections
 {
     /// <summary>
-    /// NAD27 UTM Projection with zone number.
-    /// Appears to be less accurate than MapControl.Nad27UtmProjection.
+    /// NAD27 Universal Transverse Mercator Projection.
     /// </summary>
     public class Nad27UtmProjection : GeoApiProjection
     {
diff --git a/MapProjections/Shared/Nad83UtmProjection.cs b/MapProjections/Shared/Nad83UtmProjection.cs
index ce7adef7..c3ddaa34 100644
--- a/MapProjections/Shared/Nad83UtmProjection.cs
+++ b/MapProjections/Shared/Nad83UtmProjection.cs
@@ -3,7 +3,7 @@
 namespace MapControl.Projections
 {
     /// <summary>
-    /// NAD83 UTM Projection with zone number.
+    /// NAD83 Universal Transverse Mercator Projection.
     /// </summary>
     public class Nad83UtmProjection : GeoApiProjection
     {
diff --git a/MapProjections/Shared/Wgs84AutoUtmProjection.cs b/MapProjections/Shared/Wgs84AutoUtmProjection.cs
new file mode 100644
index 00000000..20c0d72d
--- /dev/null
+++ b/MapProjections/Shared/Wgs84AutoUtmProjection.cs
@@ -0,0 +1,59 @@
+using System;
+
+namespace MapControl.Projections
+{
+    /// <summary>
+    /// WGS84 Universal Transverse Mercator Projection with
+    /// automatic zone selection from projection center.
+    /// </summary>
+    public class Wgs84AutoUtmProjection : Wgs84UtmProjection
+    {
+        private readonly string autoCrsId;
+
+        public Wgs84AutoUtmProjection()
+            : this(MapControl.Wgs84AutoUtmProjection.DefaultCrsId)
+        {
+            // XAML needs parameterless constructor
+        }
+
+        /// <summary>
+        /// When the crsId parameter is null or empty, the projection will use EPSG:32***.
+        /// </summary>
+        public Wgs84AutoUtmProjection(string crsId)
+            : base(31, true)
+        {
+            autoCrsId = crsId;
+
+            if (!string.IsNullOrEmpty(autoCrsId))
+            {
+                CrsId = autoCrsId;
+            }
+        }
+
+        public override Location Center
+        {
+            get => base.Center;
+            protected set
+            {
+                if (!base.Center.Equals(value))
+                {
+                    base.Center = value;
+
+                    var lon = Location.NormalizeLongitude(value.Longitude);
+                    var zone = (int)Math.Floor(lon / 6d) + 31;
+                    var north = value.Latitude >= 0d;
+
+                    if (Zone != zone || IsNorth != north)
+                    {
+                        SetZone(zone, north);
+
+                        if (!string.IsNullOrEmpty(autoCrsId))
+                        {
+                            CrsId = autoCrsId;
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/MapProjections/Shared/Wgs84UtmProjection.cs b/MapProjections/Shared/Wgs84UtmProjection.cs
index 11784408..c2add366 100644
--- a/MapProjections/Shared/Wgs84UtmProjection.cs
+++ b/MapProjections/Shared/Wgs84UtmProjection.cs
@@ -4,8 +4,7 @@ using System;
 namespace MapControl.Projections
 {
     /// <summary>
-    /// WGS84 UTM Projection with zone number and north/south flag.
-    /// See https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordinate_system.
+    /// WGS84 Universal Transverse Mercator Projection.
     /// </summary>
     public class Wgs84UtmProjection : GeoApiProjection
     {
@@ -36,45 +35,4 @@ namespace MapControl.Projections
             CoordinateSystem = ProjectedCoordinateSystem.WGS84_UTM(Zone, IsNorth);
         }
     }
-
-    /// <summary>
-    /// WGS84 UTM Projection with automatic zone selection from projection center.
-    /// </summary>
-    public class Wgs84AutoUtmProjection : Wgs84UtmProjection
-    {
-        public Wgs84AutoUtmProjection()
-            : this(MapControl.Wgs84AutoUtmProjection.DefaultCrsId)
-        {
-            // XAML needs parameterless constructor
-        }
-
-        public Wgs84AutoUtmProjection(string crsId)
-            : base(31, true)
-        {
-            CrsId = crsId;
-        }
-
-        public override Location Center
-        {
-            get => base.Center;
-            protected set
-            {
-                if (!base.Center.Equals(value))
-                {
-                    base.Center = value;
-
-                    var lon = Location.NormalizeLongitude(value.Longitude);
-                    var zone = (int)Math.Floor(lon / 6d) + 31;
-                    var north = value.Latitude >= 0d;
-
-                    if (Zone != zone || IsNorth != north)
-                    {
-                        var crsId = CrsId;
-                        SetZone(zone, north);
-                        CrsId = crsId;
-                    }
-                }
-            }
-        }
-    }
 }