Photoshop Elements does not support Photo Filters and Curves, so this example will use Photoshop CS to extend the example in the Layers page and the Clone page.   The result from the Layers page yielded the image shown in Fig. 1 below.  The Clone page eliminated the edge artifact where the sky meets the land.  We will first apply a warming Photo Filter layer to the land, but not to the sky, in order to remove blue cast haze over the canyon.  We will also replace the sky Levels layer to a Curves layer adjustment.  The resulting image is shown in Fig. 2.  At the end of this page, we will give some close-up views.
 

Fig. 1.  Before (from Layers page)

Fig. 2.  After all of the changes below

Select the Land

• Select > Load Selection and then select the Sky option from the drop down menu. Click OK.  Note that we saved that selection in the Layers page.
• Select > Inverse.  This inverts the selection so that we now have the land selected.
• Select > Feather  and then input a number.  I used 2.  Click OK.
• Layer > New Adjustment Layer > Photo Filter.  The defaults are fine for the first dialog box, so click OK.
• The dialog box in Fig. 3 appears with the default Density of 25% and the default Warming Filter (85).  I increased the Density to 34% for no good reason at all, other than to change something.
• Click OK.  The resulting image is displayed in Fig. 2 above by looking only at the land part of the image, not the sky.  The change is subtle, but the canyon at a distance looks much nicer without the blue cast.

A VIP note for applications where the image has near white regions is to click OFF the Preserve Luminosity check box.  With it checked on, the near white regions will remain white because the high luminosity is preserved.  With it checked off, the area will become darker and pick up more of the filter color.  This is an option when you have blown out highlights and you would probably use it only on a selection of the highlights.

Curves Layer adjustment to the sky:

• Before adjusting the sky, go to the Layers window and uncheck the Layer for the Sky Levels adjustment done on the Layers page.
• Select > Load Selection and then select the Sky option from the drop down menu. Click OK.
• Select > Feather.  Input a very small number, such as 1 or 2.  I used 2 in this example.
• Layer > New Adjustment Layer > Curves.  In the dialog box, I left the default Mode of Normal.   Click OK.
• The dialog box in Fig. 4 appears, except that there is a 45 degree straight line drawn.  I first dragged the curve downward on the left side (dark side), and then I dragged the curve upward a little on the right side (light side).  With all adjustments, toggle the Preview to see what is going on.
• Click OK.  The resulting image is displayed in Fig. 2 above by looking only at the top part of the image.

Fig. 3  Photo Filter dialog

Fig. 4  Curves dialog

The following three figures show a portion of the images at full pixel resolution (of this old 2MP image).  Fig. 4 is the original image, Fig. 2 is the image after the adjustments in the Layers page, and Fig. 3 shows the results of this page, together with the Clone page that removed the edge artifacts.
 

Fig.1 Original image
Fig. 2 Result from Layers page
Fig. 3 Result from this page and the Clone page