Core Research Center


The CRC's extensive rock core and cuttings collection is available for study by interested parties by appointment only. Contact us at CRC@USGS.GOV or (303) 202-4851 to schedule an appointment. Please review our FAQs for help in planning your visit.


Policy Updates and Reminders

Off-Site Use of CRC Core

In order to preserve the integrity of USGS Core Research Center cores, we will no longer be shipping cores off-site for workshops or displays. We will continue to allow local (Denver metro area) shipping for non-destructive analysis and core slabbing. We offer free workshop space and associated support services, and we encourage our stakeholders to take advantage of this by hosting workshops at the CRC. This new policy is intended to allow us to continue to provide you with the highest quality research and educational materials.

Privately-Owned Cores Brought to the CRC for Core Workshops

Workshops held at the CRC should primarily feature core from the CRC collection.  Non-USGS core may be brought in for comparison, but it must be less than 25% of the total amount of core used for the workshop.  The workshop sponsor assumes all responsibility for the privately-owned cores while at the CRC and in transit.

Amount of Material Allowed for Each Day of a CRC Appointment

The list of requested cores or cuttings must be submitted by noon on the business day prior to the appointment.  The list should be in priority order.  Before opening time on the scheduled day, the CRC staff will bring out as many of the requested wells as will fit in the allotted space.  No additional core or cuttings will be gotten out during the rest of that day.  If a visit is scheduled on consecutive days, the CRC staff will bring out a different set of wells for each day.  Please plan for the appropriate number of days.

Important Notice Regarding Real ID Act Requirements for Entry to Federal Facilities

As of October 10, 2018, all states and territories are either compliant with the Real ID act or have extensions until 2019. The extension dates vary, ranging from January to October, so please check your state.  Compliance status may affect TSA checkpoints or entry to Federal facilities including the Denver Federal Center - home of the CRC. PLEASE NOTE THAT EVEN IF YOUR STATE IS LISTED AS COMPLIANT, IF YOU HAVE AN OLDER LICENSE THAT DOES NOT MEET THE REAL ID ACT CRITERIA, YOU MAY HAVE DIFFICULTY ENTERING THE DENVER FEDERAL CENTER. The Real ID Act was passed by Congress in 2005, based on recommendations from the 9/11 Commission. Please check the DHS website for the latest information on the compliance status of your state. If your ID was issued by a non-compliant or recently compliant state / territory, you might consider acquiring an alternative ID such as a U.S. Passport or U.S. Passport card. More information about the REAL ID Act of 2005, and Secure Driver’s Licenses can be found on this page from the Department of Homeland Security:

The CRC apologizes for any inconvenience to our visitors. 


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Year Published: 2019

The rise of an apex predator following deglaciation

AimSea otters (Enhydra lutris) are an apex predator of the nearshore marine community and nearly went extinct at the turn of the 20th century. Reintroductions and legal protection allowed sea otters to re‐colonize much of their former range. Our objective was to chronicle the colonization of this apex predator in Glacier Bay, Alaska, to help...

Hooten, Mevin B.; Esslinger, George G.

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Year Published: 2019

A hierarchical Bayesian approach for handling missing classification data

Ecologists use classifications of individuals in categories to understand composition of populations and communities. These categories might be defined by demographics, functional traits, or species. Assignment of categories is often imperfect, but frequently treated as observations without error. When individuals are observed but not classified,...

Alison C. Ketz; Therese L. Johnson; Hooten, Mevin B.; N. Thompson Hobbs

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Year Published: 2019

On the relationship between conditional (CAR) and simultaneous (SAR) autoregressive models

We clarify relationships between conditional (CAR) and simultaneous (SAR) autoregressive models. We review the literature on this topic and find that it is mostly incomplete. Our main result is that a SAR model can be written as a unique CAR model, and while a CAR model can be written as a SAR model, it is not unique. In fact, we show how any...

Jay M. Ver Hoef; Ephraim M. Hanksb; Hooten, Mevin B.