Alternative D: Skyline Interchange to Lower Ocotillo Road
The mountains located immediately west of the "D" mark on this map are the Little Rincons, with the Rincons lying further west of them (and the Happy Valley headwaters of the Paige Wash in between).
Where the route leaves the I-10 on the high terrace west of Benson, the location appears to take off not at, but to the east of the current Mescal Road exit (297), rather it takes off at Exit 299 (The "Skyline Interchange"). (At present the roadway indicated at this exit ends abruptly a short distance to the north.) All the land located immediately on the north side of the Interstate all the way to the Pima County line is marked as Private Land, so development could occur anywhere near this Interchange.
From that point Alternative "D" is shown to run almost directly north through State Land to a point directly east of Kiper Spring near the Ash Creek Wash, where it turns northeastward into Private Land and runs presumably just west of the existing subdivision (shown on map below) located just southwest of Willow Lake. Just north of the subdivision it would connect with existing Ocotillo Road, the course of which it roughly parallels (though it would no doubt drastically straighten the hooks and curves of that old dirt road as it runs north (to the west of the hills lying just west of the Narrows).
Significant Springs along a Right-of-Way
Below see some brief elaboration of details. As designated on the Alternatives map, "D" would run right through the several springs shown in the middle of the map below. Nearly all the relevant land here is Private.
Below (courtesy of Europa Technologies Inc. by way of Google Earth) is an aerial view of the Kiper Springs-to-Willow Lake location. The Kiper Spring location is marked by the dark strip to the far left (just west of the low ridge where a very minimalist existing dirt road runs). Ash Creek Wash runs left-to-right across the middle of the image, while the area marked "Springs" on the map above (there are apparently many of them) is marked on the view below with a red X. The springs are located in the dark inverted "V" at the source of the wash that runs beyond it.
Ocotillo Road Vicinity Northward
While this part would appear to be fairly easy sailing for roadbuilders, there are springs in the area. Local residents and ecologists should take a range of possible impacts into account in assessing this Alternative.