My husband and I had finished a short hike off of Sand Flats Road and were returning home. We turned east along Sand Flats Road from a side road and were directly facing the Moab Rim. I immediately saw two slowly moving objects going from south to north, just below the top of the Rim and directly opposite our truck. They attracted my attention because of their movement, and they were lighter in color than the red/orange rock of the cliffs. They appeared to be moving very slowly at a constant velocity, slower than what I would expect from aircraft. I thought that they were perhaps ultralights. My husband is an ex-pilot, so I asked my husband to stop the truck, and we both got out to observe the objects. The sun was behind Rim at this time,so we were not looking directly into the sun. The objects were flying in what my husband called an "echelon" formation," with one object flying slightly behind and off flank to the other. There was a distinct separation between the objects. Their relative positions did not change for the entire time of observation, which we estimated to be approximately 2 minutes; however, we did not time the period with a watch. My husband thought that the object to the rear was slightly larger (nearer) than the lead object, putting them in a right echelon formation. I was not able to discriminate between sizes of the two objects. My husband was certain that we were not observing ultralights because the objects maintained constant relative postions for the entire observation time.Since the top of the Rim has some irregularities, I thought that we may be able to see the objects' silouettes at some point since they were just below the Rim. From our viewpoint,though, the objects travelled just below the top of the Rim for the entire 2 minutes. At one point, however, sunlight from a break in the rocks illuminated the two objects, which then appeared as two bright shining points of light, so they seemd to be metallic. The illumination was brief, perhaps two seconds as they continued northward along the cliff face. We were able to observe the objects until the cliff face dropped suddenly in elevation. At that point, the objects immeidately disappeared against the sky, south of the Portal. We were able to locate our position relative to the objects on topo maps when we got home. We are fairly confident of the distances we estimated. In summary:Feelings: We agreed that we could not identify the objects. We also agreed to make this report because we hope that someone in the Moab Valley may have also seen them and could provide insight/explanation.Shape of objects: Our elevation in the truck was approximately the same as the objects, so we were looking from a side view. Roughly diamond-shaped, but flat on the bottom; a skewed trapezoidal shape; the vertical dimension was offset to a vertical centerline, as viewed from the side, so they were slightly assymmetric. Color: My husband described them as light gray. I could tell that they were lighter in color than the background rocks but can not definitely describe them as gray. Texture: To me, although the outline of their shapes was definitely discernable, they seemd a little "fuzzy." Distance from viewpoint to objects: Approximately 4.57 miles, as estimated froma 7.5" topo, Sand Flats Road to cliff face.Distance travelled along front of Moab Rim during approximate 2 minute time period: 2.2 miles.Size of objects: We both agreed that if we held a hand out in front of us, each object would be the size of half our thumbnails. Using the distance from our position to the Rim, we extrapolated tha size of the objects and estimate each one to be about 200+ feet long.Apparent velocity: Approximately 60 mph.