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Frequently Asked Questions

Helpful Hints

  1. What cores/cuttings are in the CRC collection?  

    The U.S. Geological Survey Core Research Center (CRC) located in Denver, CO, maintains one of the most diverse publicly accessible core and cuttings collections in the country. Currently, the CRC houses cores from over 9,000 wells representing 1,700,000 feet of core from 33 states and cuttings from 52,000 wells representing 238,000,000 feet of drilling in 27 states. Most of the material is from oil/gas and mineral wells in the Rocky Mountain Region.

  2. How do I find out if core/cuttings are available to view and/or sample?  

    Information about the CRC Collection can be obtained by going to the CRC Web site. Click on the “Wells” link on the left-hand side of the page.

  3. I want to look at core or cuttings, what do I do?  

    Make an appointment by either calling the front desk at (303) 202-4851 or e-mailing us at

  4. What information do I need to make an appointment?  

    To make an appointment call (303) 202-4851 or email the CRC ( and provide the following:

    • the CRC library number for the cores/cuttings
    • the depths you want to view
    • your name
    • your company/entity name
    • your e-mail address
    • your phone number
    • the day(s) you’d like to view the cores/cuttings
    • which well(s) you would like to view first
    • if you are hoping to take samples

    The library number for cores is a letter followed by three numbers (for example, A569); for cuttings it is two letters followed by five numbers (for example, CZ08825). Please check our online catalog for the availability of the depths of interest.

  5. How much advance notice does the CRC need to schedule appointments?  

    Appointments should be made at least a week in advance and are on a first-come, first-serve basis. The more notice the CRC receives, the better your chances of getting an appointment on the day of your choice.

  6. What are your hours of operation?  

    The CRC is open Monday thru Friday from 8:00 am to 3:00 pm when the Denver Federal Center is open. The Denver Federal Center is closed to the public on weekends, Federal Holidays, and on some days of heavy snowfall. Check the USGS Denver Weather Notification website at for USGS Denver Federal Center closure during snow storms or call us for information.

  7. How do I get to the CRC?  

    See Maps and directions.

  8. What do I need to get onto the Denver Federal Center?  

    The Denver Federal Center is a secure facility.

    To get in you need one of the following:

    Enter at one of the three visitor’s gates (See Map); tell the guard you are visiting the Core Research Center in Building 810.

  9. What is your mailing address and phone numbers?  

    USGS Core Research Center
    25046 Denver Federal Center
    MS 975
    Denver, CO 80225
    Phone 303-202-4851 (Main CRC Number)
    FAX 303-202-4856

  10. How much core can I view at a time?  

    You can reserve up to two tables per appointment. This amounts to 200-400 feet of archived core or 150-300 feet of full core. If you want to view more than will fit in the space please provide a prioritized list of the cores. We will bring out as much as will fit. We no longer provide a same-day switch out, but if your visit spans multiple days you can have a different set of cores each day. Please plan for the appropriate number of days.

  11. What is archived core?  

    Archived core is the smaller (1/3) slab of a slabbed core which the CRC stores in tray-style boxes.

  12. How can I tell if a core is archived, full core, etc.?  

    Archived core library numbers are between A001 to F999. Library numbers between R001 to W999 are either full core, butts, slabbed, or split core. This information can also be found under the "Type" column in the core list.

  13. Once I’ve found the wells I want in your database, how do I save a list of them?  

    A list of wells created from a search of the Well Catalog can be saved in csv (opens in Excel), pdf or xml format. Scroll down to the bottom of the list. Find the word "Export" followed by the icons and file names for the types of files. Click on the type of file you want and a box will come up that will allow you to save the file.

  14. Can I search by well name, API number, etc.?  

    The Text-Based Search allows searching by well name, operator name, field name, CRC library number, township, range, section and by one or more API numbers. See the Search Tips page for more information on how to use the Text-Based and Map-Based search tools.

  15. How do I tell if a core or cuttings have data, photos or thin sections available?  

    The core and cuttings lists have a column for thin sections and a column for analysis containing "YES" or "no" to indicate if a well has any of these items. The core list has a similar column that indicates if there are photos. To see and download the reports, photos or thin section images click on the Library Number and then click the links on the following page for the individual items.

  16. When the Search Results list has "YES" in the photos or thin sections or data column(s) how do I view these additional files?  

    To see and download reports, photos or thin section images click on the Library Number in the Search Results list. The Library Number is in the 7th column from the left in the search results. It is one letter followed by three numbers for cores and two letters followed by five numbers for cuttings. Clicking the Library Number produces a new page with links to view and download the files.

  17. What is your sampling policy?  

    See the Core Sampling Policy or the Cuttings Sampling Policy for complete information.

  18. Can I check out data, photos or thin sections?  

    Digital versions of all of the data files are available from our website where they can be viewed and downloaded. The data files contain the results of testing on samples taken while the core or cuttings have been part of the CRC collections. We do not have results for analyses done previously. Most of the wells do not have data.

    We are still working on photographing all of the cores. All available core photos can be viewed and downloaded from the web.

    Images of the thin sections can be viewed and downloaded from the web. The actual thin sections can be checked out for 30 days. See the Thin Section Loan Policy for more information.

  19. Can you ship me data, photos or thin sections?  

    No. Data and photos can be downloaded from the web. If you want to check out thin sections, you need to come to the CRC.

  20. Can I check out core or cuttings from the facility?  

    No, you cannot check out core or cuttings. Core can leave for slabbing and, with prior approval, certain non-destructive tests. See the Core Sampling Policy for more information.

  21. Is public internet access available at the facility?  

    We do not offer wireless access or printing services.

  22. How do I get a core slabbed?  

    Contact us first about the core you want slabbed, then contact the core processing company. The company needs to coordinate with us on a pick up and return time for the core. You pay the core processing company for the work completed. See the Core Sampling Policy for more information.

  23. Whom do I contact about donating core or cuttings?  

    Contact the CRC at (303)-202-4851. We ask some initial questions to determine if your donation is unique and valuable to our collection. We need a completed Well Information form and a Transmittal Agreement form faxed to (303)-202-4856 for each well. Once the paperwork is reviewed, we will inform you of our decision. See the General Collections Accession Policy for more information.

  24. I have an appointment but the weather is terrible. How do I know if the CRC is open?  

    Call the CRC at (303)-202-4851 to see if the staff has been able to get in. You can also check the USGS Denver Weather Notification website at to see if the USGS / Denver Federal Center is open. Announcements of delayed arrival or closure will be posted by 5:30 a.m. If the USGS / Denver Federal Center is closed the CRC will also be closed.