diff --git a/SimPEG/Mesh/TreeMesh.py b/SimPEG/Mesh/TreeMesh.py
index 0cd0cca3..b35dac1a 100644
--- a/SimPEG/Mesh/TreeMesh.py
+++ b/SimPEG/Mesh/TreeMesh.py
@@ -887,6 +887,28 @@ class TreeMesh(InnerProducts, BaseMesh):
             self._faceDiv = Utils.sdiag(1/VOL)*D*Utils.sdiag(S)
         return self._faceDiv
 
+    @property
+    def edgeCurl(self):
+        """Construct the 3D curl operator."""
+        assert self.dim > 2, "Edge Curl only programed for 3D."
+
+        if getattr(self, '_edgeCurl', None) is None:
+            self.number()
+            # TODO: Preallocate!
+            I, J, V = [], [], []
+            for face in self.faces:
+                for edge in face.edges:
+                    j = face.edges[edge].index
+                    I += [face.num]*len(j)
+                    J += j
+                    isNeg = lambda e: {'0':True,'1':False,'2':True,'3':False}[e[1]]
+                    V += [-1 if isNeg(edge) else 1]*len(j)
+            C = sp.csr_matrix((V,(I,J)), shape=(self.nF, self.nE))
+            S = self.area
+            L = self.edge
+            self._edgeCurl = Utils.sdiag(1/S)*C*Utils.sdiag(L)
+        return self._edgeCurl
+
     @property
     def nodalGrad(self):
         if getattr(self, '_nodalGrad', None) is None:
diff --git a/SimPEG/Tests/test_TreeMesh.py b/SimPEG/Tests/test_TreeMesh.py
index acdc4308..7a744d0a 100644
--- a/SimPEG/Tests/test_TreeMesh.py
+++ b/SimPEG/Tests/test_TreeMesh.py
@@ -508,6 +508,10 @@ class SimpleOctreeOperatorTests(unittest.TestCase):
         self.assertTrue((self.tM.nodalGrad - self.oM.nodalGrad).toarray().sum() == 0)
         self.assertTrue((self.tM2.nodalGrad - self.oM2.nodalGrad).toarray().sum() == 0)
 
+    def test_edgeCurl(self):
+        self.assertTrue((self.tM.edgeCurl - self.oM.edgeCurl).toarray().sum() == 0)
+        # self.assertTrue((self.tM2.edgeCurl - self.oM2.edgeCurl).toarray().sum() == 0)
+
     def test_InnerProducts(self):
         self.assertTrue((self.tM.getFaceInnerProduct() - self.oM.getFaceInnerProduct()).toarray().sum() == 0)
         self.assertTrue((self.tM2.getFaceInnerProduct() - self.oM2.getFaceInnerProduct()).toarray().sum() == 0)