David Hill Earthcache EarthCache

The David Hill Earthcache is located in northeastern New Mexico east of Mosquero along NM Hwy 39.

The Great Plains east of the Rocky Mountains in Canada and the United States are characterized by vast expanses of prairie lands. In eastern New Mexico, the area is referred to generally as the High Plains. David Hill, in Harding County, is part of the broad escarpment separating two portions of the High Plains. The difference in elevation is roughly 750 feet, and the road winds along sweeping switchbacks from top to bottom. Fortunately, we can experience the dramatic transition first-hand traveling along La Frontera del Llano Scenic Byway (NM Hwy 39).

The geology underlying La Frontera del Llano Scenic Byway between Abbott and Mills varies in type and geologic age. Closest to Abbott are silt and sand eolian (wind) deposits from the Quaternary Period (Holocene epoch to Middle Pleistocene stage). Traveling south are shales from the Cretaceous Period, including the Greenhorn Formation, Graneros Shale, and Carlile Shale, all of which are also found in neighboring states.

Near Mills the geology is largely sedimentary material from the Tertiary period, and Hwy 39 generally follows a wide northwest/southeast band of this sedimentary material as it passes through Roy and moves southeast to Mosquero. Heading east from Mosquero, the road continues primarily on sedimetary deposits until it reaches David Hill.

At David Hill, the road passes through geologic material from five distinct periods before arriving at the bottom of the escarpment. From west to east are alluvial and eolian deposits from the Tertiary Period, sandstone and shale from the Cretaceous Period, landslide deposits and colluvium dating from the Quaternary Period, and gray/red outcrops of the Morrison Formation from the Jurrasic Period. Entrada Sandstone (Jurrasic) is also visible at the east end of David Hill and south of the base. Closest to the base is a band of sedimentary material from the Upper Chinle Group of the Triassic Period.

From the base of David Hill south toward Logan, Hwy 39 traverses over alluvium, a mix of sediments deposited by water during the Holocene epoch to Upper Pleistocene stage of the Quaternary Period. Immediately west of the highway is the Bull Canyon Formation of Chinle Group, which is comprised primarily of mudstone and sandstone.

The primary earthcache coordinates mark the top of the escarpment at the west side of David Hill. It will also be necessary to stop at the bottom of the escarpment and part of the way up or down, depending upon your direction of travel. Each set of coordinates is near a pull-off from the highway, but please exercise caution when leaving or entering the road.

Sample Logging Photo Showing David Hill Descent

To Log this Earthcache

1) Visit all three sets of coordinates. Record elevation readings at the top and bottom of the escarpment.

2) Have your photograph taken at the top and the bottom of the site with your GPSr so that some portion of the ascending and descending roadway is visible, as shown in the sample logging photos. For solo cachers, a photo of your hand holding your GPSr at the sites is certainly fine. If your GPSr and phone are in one unit (e.g., an iPhone with Geocaching app), creative photos of your choosing at the sites are also acceptable.

3) Immediately before logging your find, e-mail the answers to the following questions using this link. Do not post the answers in your log!

Go to these coordinates: N 35° 47.400 W 103° 49.301 - the pull-off is on the right as you climb the hill. Questions - Looking perpendicular from the roadway you will see a large object that has fallen. Are there other features like it on David Hill? How do you suppose it came rest in this position? Best guesses are okay! If weather or other conditions prevent you from completing this portion of the earthcache, please let me know.

4) Log your find, and include the elevations you recorded at the top and bottom. Please also upload your photographs when you log your find. Logs without at least two photographs will be deleted, hence the (albeit modest) difficulty rating.

Sample Logging Photo Showing David Hill Ascent

David Hill was named for the ghost town of David, New Mexico, which was near the base of the hill. The town was large enough to support a post office from 1915 to 1922. A cemetery is about all that remains of the town.

My abrupt introduction to David Hill was in 1981; I was traveling with friends from Cimarron to Tucumcari, and was asleep in the rear of a 1960s VW minivan when we started down the hill. Too much speed, a sharp turn, and I was thrown from one side to the other. The driver regained control, but several miles from the bottom we had a massive blowout, no doubt from damage sustained high on the hill. My subsequent visits have been less eventful, and this is my favorite way to approach the mountains from Amarillo.

Information for this earthcache was gathered from several sources, including New Mexico Tech's New Mexico Bureau of Geology & Mineral Resources map page.