diff --git a/CHANGES.md b/CHANGES.md
index 2ef016f2c36f..983146dd573c 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,11 @@
 Change Log
 ==========
 
+### 1.51 - 2018-11-01
+
+##### Fixes :wrench:
+* Fixed an issue where `pickPosition` would return incorrect results when called after `sampleHeight` or `clampToHeight`. [#7113](https://github.com/AnalyticalGraphicsInc/cesium/pull/7113)
+
 ### 1.50 - 2018-10-01
 
 ##### Breaking Changes :mega:
diff --git a/Specs/Scene/PickSpec.js b/Specs/Scene/PickSpec.js
index 26812206a792..266497875103 100644
--- a/Specs/Scene/PickSpec.js
+++ b/Specs/Scene/PickSpec.js
@@ -1,6 +1,8 @@
 defineSuite([
+        'Core/Cartesian2',
         'Core/Cartesian3',
         'Core/Cartographic',
+        'Core/Color',
         'Core/Ellipsoid',
         'Core/FeatureDetection',
         'Core/GeometryInstance',
@@ -25,8 +27,10 @@ defineSuite([
         'Specs/createScene',
         'Specs/pollToPromise'
     ], 'Scene/Pick', function(
+        Cartesian2,
         Cartesian3,
         Cartographic,
+        Color,
         Ellipsoid,
         FeatureDetection,
         GeometryInstance,
@@ -57,7 +61,7 @@ defineSuite([
     var camera;
     var largeRectangle = Rectangle.fromDegrees(-1.0, -1.0, 1.0, 1.0);
     var smallRectangle = Rectangle.fromDegrees(-0.0001, -0.0001, 0.0001, 0.0001);
-    var offscreenRectangle = Rectangle.fromDegrees(-45.0, -1.0, -43.0, 1.0);
+    var offscreenRectangle = Rectangle.fromDegrees(-45.0002, -1.0002, -45.0001, -1.0001);
     var primitiveRay;
     var offscreenRay;
 
@@ -1078,4 +1082,69 @@ defineSuite([
             scene.context._depthTexture = depthTexture;
         });
     });
+
+    it('calls multiple picking functions within the same frame', function() {
+        if (!scene.clampToHeightSupported || !scene.pickPositionSupported) {
+            return;
+        }
+
+        createSmallRectangle(0.0);
+        var offscreenRectanglePrimitive = createRectangle(0.0, offscreenRectangle);
+        offscreenRectanglePrimitive.appearance.material.uniforms.color = new Color(1.0, 0.0, 0.0, 1.0);
+
+        scene.camera.setView({ destination : offscreenRectangle });
+
+        // Call render. Lays down depth for the pickPosition call
+        scene.renderForSpecs();
+
+        // Call clampToHeight
+        var cartesian = Cartesian3.fromRadians(0.0, 0.0, 100000.0);
+        expect(scene).toClampToHeightAndCall(function(cartesian) {
+            var expectedCartesian = Cartesian3.fromRadians(0.0, 0.0);
+            expect(cartesian).toEqualEpsilon(expectedCartesian, CesiumMath.EPSILON5);
+        }, cartesian);
+
+        // Call pickPosition
+        expect(scene).toPickPositionAndCall(function(cartesian) {
+            var expectedCartesian = Cartographic.toCartesian(Rectangle.center(offscreenRectangle));
+            expect(cartesian).toEqualEpsilon(expectedCartesian, CesiumMath.EPSILON5);
+        });
+
+        // Call clampToHeight again
+        expect(scene).toClampToHeightAndCall(function(cartesian) {
+            var expectedCartesian = Cartesian3.fromRadians(0.0, 0.0);
+            expect(cartesian).toEqualEpsilon(expectedCartesian, CesiumMath.EPSILON5);
+        }, cartesian);
+
+        // Call pick
+        expect(scene).toPickPrimitive(offscreenRectanglePrimitive);
+
+        // Call clampToHeight again
+        expect(scene).toClampToHeightAndCall(function(cartesian) {
+            var expectedCartesian = Cartesian3.fromRadians(0.0, 0.0);
+            expect(cartesian).toEqualEpsilon(expectedCartesian, CesiumMath.EPSILON5);
+        }, cartesian);
+
+        // Call pickPosition on translucent primitive and returns undefined
+        offscreenRectanglePrimitive.appearance.material.uniforms.color = new Color(1.0, 0.0, 0.0, 0.5);
+        scene.renderForSpecs();
+        expect(scene).toPickPositionAndCall(function(cartesian) {
+            expect(cartesian).toBeUndefined();
+        });
+
+        // Call clampToHeight again
+        expect(scene).toClampToHeightAndCall(function(cartesian) {
+            var expectedCartesian = Cartesian3.fromRadians(0.0, 0.0);
+            expect(cartesian).toEqualEpsilon(expectedCartesian, CesiumMath.EPSILON5);
+        }, cartesian);
+
+        // Call pickPosition on translucent primitive with pickTranslucentDepth
+        scene.pickTranslucentDepth = true;
+        scene.renderForSpecs();
+        expect(scene).toPickPositionAndCall(function(cartesian) {
+            var expectedCartesian = Cartographic.toCartesian(Rectangle.center(offscreenRectangle));
+            expect(cartesian).toEqualEpsilon(expectedCartesian, CesiumMath.EPSILON5);
+        });
+    });
+
 }, 'WebGL');
diff --git a/Specs/addDefaultMatchers.js b/Specs/addDefaultMatchers.js
index cc5dd27976f3..a32d118ad25a 100644
--- a/Specs/addDefaultMatchers.js
+++ b/Specs/addDefaultMatchers.js
@@ -439,6 +439,30 @@ define([
                 };
             },
 
+            toPickPositionAndCall : function(util, customEqualityTesters) {
+                return {
+                    compare : function(actual, expected, x, y) {
+                        var scene = actual;
+                        var canvas = scene.canvas;
+                        x = defaultValue(x, canvas.clientWidth / 2);
+                        y = defaultValue(y, canvas.clientHeight / 2);
+                        var result = scene.pickPosition(new Cartesian2(x, y));
+
+                        var webglStub = !!window.webglStub;
+                        if (!webglStub) {
+                            // The callback may have expectations that fail, which still makes the
+                            // spec fail, as we desired, even though this matcher sets pass to true.
+                            var callback = expected;
+                            callback(result);
+                        }
+
+                        return {
+                            pass : true
+                        };
+                    }
+                };
+            },
+
             toReadPixels : function(util, customEqualityTesters) {
                 return {
                     compare : function(actual, expected) {