S. 3599

Prehistoric Trackways National Monument Establishment Act

Statement of
Chad Calvert
Principal Deputy Assistant Secretary Land and Minerals Management
U.S. Department of the Interior
Senate Energy & Natural Resources Committee
S. 3599, Prehistoric Trackways National Monument Establishment Act

September 27, 2006

Thank you for the opportunity to testify in support of S. 3599, the Prehistoric Trackways National Monument Establishment Act. We are excited about the discovery of these important prehistoric trackways on Bureau of Land Management (BLM) managed land in New Mexico and agree with Senator Bingaman that we must permanently protect these exceptional resources.


The Paleozoic trackways site is located on public land managed by the BLM in the Robledo Mountains in south-central New Mexico. The area is located within a sequence of sedimentary rocks representing a transition zone between marine and continental environments that existed during the early Permian period (280 million years ago). During times of higher sea level, limestone formed. The limestones contain a variety of invertebrate fossils. As the sea retreated, a tidal flat environment developed and sand, silt and clay dominated deposition. The sandy siltstones contain a variety of sedimentary structures, including raindrop impressions, mudcracks, and ripple laminations. These sandy siltstones are known to contain fossil tracks of land dwelling vertebrates which roamed New Mexico before the age of the dinosaurs.

In 1987, Las Cruces resident Jerry MacDonald discovered a major Paleozoic trackways area. Over the next few years, other significant sites were also discovered by MacDonald. The resources that have been found in the Robledos are considered by scientists who have examined them to be the largest, and scientifically, the most important Paleozoic fossil footprint discovery ever made in the western United States and possibly the world. The trackways are extremely diverse and varied, and appear to represent a very broad spectrum of ancient animal life; including the 11 foot long, fin-backed Dimetrodon and the big headed amphibian Batrachichnus, as well as other reptiles, amphibians, insects and other invertebrates. They also represent not just an occasional footprint, but entire trackways where different animals had left a record of activity. This is considered the best locality in the world for early Permian tetrapod trackways.

In 1990, the Congress passed legislation sponsored by Senator Bingaman along with Senator Domenici and Representative Skeen which withdrew 736 acres around the trackway site and called for a study of the area. In 1993, the BLM using its resource management planning process designated 720 acres as a Research Natural Area (RNA). The study was completed in 1994 and gave a range of alternatives for protection, most of which were implemented, including an agreement BLM initiated with the New Mexico Museum of Natural History and Science to ensure professional curation of fossils. The Museum holds the largest collection of these important fossils to allow for scientific study and interpretation from around the world. In fact, the public is now able to access the collection on the Museum’s website. As part of the BLM’s ongoing planning process, additional protections for the area are being considered.

Jerry MacDonald’s excavation and collection of material from the trackways site is now preserved in the New Mexico Museum of Natural History and Science, the Carnegie Museum, the Smithsonian, the Los Angeles County Museum, and the City of Las Cruces Natural History Museum.

S. 3599

The legislation before the Committee today would designate 5,367 acres of public land in Doña Ana County as the Prehistoric Trackways National Monument. The legislation’s stated goal is to conserve, protect, and enhance the unique and nationally important paleontological, scientific, educational, scenic, and recreational resources and values of the area. We strongly support those goals and legislation to implement them. We would like the opportunity to work with Senator Bingaman, as well as Senator Domenici and the Committee staff, on amendments which we believe can improve the legislation.

Section 5(a)(3) of the bill directs the BLM to “manage public land adjacent to the Monument in a manner that is consistent with the protection of the resources and values of the monument.” The intent of this provision is not clear, and it is not clear how the BLM would implement it. In addition, we would encourage the sponsor and the Committee to include within the monument boundaries all public lands intended for protection without setting up de facto buffer zones. Section 5(d) of the bill gives priority to exhibiting and curating the resources from the monument in Doña Ana County, New Mexico. Many, if not most, of the significant specimen resources will remain in situ for study. Those that are removed for scientific purposes deserve the highest level of curation. At this time we are concerned that there may not be adequate facilities in Doña Ana County for curation at the level afforded by the excellent facility at the New Mexico Museum of Natural History and Science. It may be preferable for curation to take place at the museum in Albuquerque and then exhibition in Doña Ana County.

The legislation in section 5(g) withdraws the area from the land, mining, mineral leasing and minerals materials laws. We generally support this withdrawal in order to protect the important paleontological resources within the proposed monument. We encourage the sponsor and the Committee to consider whether it might be wise to exclude a small 90 acre parcel on the southern boundary of the proposed monument. Within this area is a ten acre site on which a mineral materials operation has existed for a number of years. Continuation of this operation should not interfere with the protection of the resources within the monument and there is strong local demand for the rock produced from the mine.

While we strongly support the concept of protecting the Prehistoric Trackways, we believe a designation of the area as a National Conservation Area (NCA) is more appropriate. The title of “National Monument” may raise the expectation of the public that this area is similar to an area like the Kasha Katuwe Tent Rocks National Monument. The visual qualities found at Tent Rocks will not be replicated at the trackways site. An NCA would provide as much as or even more protection for the trackways than a National Monument, depending on the legislation written, and may be preferable.

Finally, we would like to clarify that the BLM does not regulate hunting on public lands, but may in some circumstances work cooperatively with the state to limit firearms in particular areas such as campgrounds or active excavation sites.


We want to express our deep appreciation to Senator Bingaman and Senator Domenici for introducing this legislation to protect the important Paleozoic Trackways in south-central New Mexico. It is critical that we protect these resources for future generations. We look forward to working cooperatively with the Committee to ensure their protection.

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