NCSU Website

National Association of State Park Directors (NASPD)

Annual Information Exchange (AIX)

Statistical Report of State Park Operations

The AIX Project Team:
NC State University: Dr. Yu-Fai Leung (Project PI), Ms. Joey Cheung (Research Assistant)

Utah State University: Dr. Jordan Smith (Project co-PI) 

Current Survey (Data Reporting Period -- July 1, 2019 through June 30, 2020) 

Latest updates (March 12, 2021): Survey launched. Data input due May 14, 2021


The National Association of State Park Directors (NASPD) Annual Information Exchange (AIX) survey, hosted by North Carolina State University, gathers information about inventory, facilities, visitation, expenses, financing and personnel for all state park units in the USA. 

Note to AIX State Liaisons: Please use the survey URL provided in our AIX Survey email to enter this year's data. Make sure you review the instructions and help videos before starting. Contact the Project Team ( if there is any question. Thank you for your participation in this year's survey. 

AIX Reports, Further Analyses and Other Outputs

  • AIX Reports and Data Sets
    • AIX reports (PDF) and data sets (Excel) from the current and past years are available at no charge to all AIX liaisons. They are also available for other users at no or a modest charge depending on the user type. Please contact the Project PI, Dr. Yu-Fai Leung ( for details
    • The AIX 2018-19 Report (PDF document and accompanying Excel data) was delivered to all state liaisons in February 2020. The hard copies were distributed in March 2020.
    • Corrections on the AIX 2011-12 Report
    • AIX Report (2012-13 Data) [Sample]
  • AIX Outlook Letters [further analyses based on AIX data from multiple years; developed by Project co-PI Dr. Jordan Smith ( since July 2013, and Dr. Chris Siderelis prior to June 2013]
  • Peer-reviewed Journal Articles (contact Project PI or co-PI for the full text)
Important Disclaimer: The following scholarly publications utilize the AIX data sets, but the analyses were performed by the authors independently of the project sponsor, NASPD. Therefore, the topic selection, methodology, results, discussion, conclusions, and/or other views expressed by the authors in these papers do not represent the views and positions of the NASPD. Other academic researchers in any discipline are also encouraged to utilize the AIX data for their own scholarly analyses that contribute to our collective understanding of America's state park system in relation to other issues and trends. Please contact the Project PI, Dr. Yu-Fai Leung ( for further details.

    • Smith, J. W., Wilkins, E., & Leung, Y.-F. (2019). Attendance trends threaten future operations of America’s state park systems. Proceedings of the National Academy of Sciences of the USA, 116(26), 12775-12780. [Abstract]
    • Smith, J. W., & Siderelis, C. (2017). Temporal trends in the operating inefficiencies of U.S. state park systems. Journal of Outdoor Recreation and Tourism, 18, 105-112. [Abstract]
    • Smith, J. W., Leung, Y.-F., Seekamp, E., Walden-Schreiner, C., & Miller, A. (2015). Projected impacts to the production of outdoor recreation opportunities across state park systems in the U.S. due to the adoption of a domestic climate change mitigation policy. Environmental Science and Policy, 48, 77-88. [Abstract]
    • Siderelis, C., & Smith, J. W. (2013). Ecological settings and state economies as factor inputs in the provision of outdoor recreation. Environmental Management, 52(3), 699-711. [Abstract]
    • Siderelis, C., Moore, R. L., Leung, Y.-F., & Smith, J. W. (2012). A nationwide production analysis of state park attendance in the United States. Journal of Environmental Management, 99, 18-26. [Abstract]
  • Conference Presentations (contact Project PI for more information)
    • Leung, Y.-F., Miller, A., Walden-Schreiner, C., Smith, J., & Ledford, L. (2017). Long-term monitoring of state park operations in the U.S.. Poster presented at the 2017 International Symposium on Society and Resource Management (ISSRM) Conference.
    • Leung, Y.-F., Smith, J. W., & Miller, A. (2014). U.S. State Parks Visitation Data from the NASPD Annual Information Exchange Project.Invited paper presented at the 2014 IUCN World Parks Congress; Sydney, NSW, Australia.
    • Miller, A. & Leung, Y.-F. (2013). The role of state parks in providing recreation opportunities: .Visitation trends in difficult economic times. Poster presented at the 2013 George Wright Society Conference on Parks, Protected Areas, and Cultural Sites; Denver, CO.
    • Leung, Y.-F., Siderelis, C., Miller, A., & Walden-Schreiner, C. (2012). A long-term state park operations database for academic research: Examples and suggestions. Poster presented at the 34th Southeastern Recreation Research Conference; Auburn, AL. [PDF Copy]