The published book I wrote about earlier, has a nice flyer with all the references. Even if you don't buy the book, this is a valuable list on bibliographies on Volunteers in Tourism.
I got the flyer from one of my feeds.
If it doesn't work, here is the bib for my paper:
Herding 6,000 volunteers
Anderson, D. H. , Lime, D. W. , & Wang, T. L. (1998). Maintaining the quality of park resources and visitor experiences. A handbook for managers. University of Minnesota.
Anderson, L. (2002). Benton MacKaye: Conservationist, planner, and creator of the Appalachian Trail. Johns Hopkins University Press.
Appalachian Trail Conservancy (ATC) . (1981). Comprehensive plan for the protection, management, development and use of the Appalachian National Scenic Trail. Appalachian Trail Conservancy.
Appalachian Trail Conservancy . (2011). A.T. corridor stewardship field: A guide to corridor monitoring and boundary maintenance for volunteers. Appalachian Trail Conservancy.
Appalachian Trail Conservancy . (2016). Appalachian trail conservancy volunteer leadership handbook. Appalachian Trail Conservancy.
Baker, M. L. , Dhungel, S. , Davenport, M. E. , Leahy, J. E. , & Bridges, C. A. (2010). An exploratoryinvestigation of the roles friends groups play in national park management. Journal of Outdoor Recreation, Education, and Leadership, 2(3), 285–300.
Benninger-Truax, M. , Vankat, J. L. , & Schaefer, R. L. (1992). Trail corridors as habitat and conduits for movement of plant species in Rocky Mountain National Park, Colorado, USA. Landscape Ecology, 6(4), 269–278. https://doi.org/10.1007/BF00129705
Birchard, W. , & Proudman, R. D. (1981). Trail design, construction, and maintenance. Appalachian Trail Conservancy.
Bowman, J. (2021, January 5). Media room. Appalachian Trail Conservancy. Retrieved January 5, 2021 from https://appalachiantrail.org/our-work/about-us/media-room/
Bratton, S. P. (2012). The spirit of the Appalachian trail: Community, environment, and belief. University of Tennessee Press.
Brian, C. (1982). New Handshake: Management Partnerships along the Appalachian Trail. Parks andRecreation. 17(6), 62, 36–42.
Bristow, R. S. (1998). Volunteer-based recreation land management. Parks and Recreation. 33(8), 70–77.
Bristow, R. S. (2004). Volunteer-based recreation land management: The eyes and ears for the Appalachian Trail. In I. Camarda (Ed.), Global challenges of parks and protected area management (pp. 71–78). Carlo Delfino.
Bristow, R. S. (2019). Altruistic adventure voluntourism: Help manage the park you visit. In I. Jenkins (Ed.), Adventure Tourism (pp. 145–154). CABI.
Bruyere, B. , & Rappe, S. (2007). Identifying the motivations of environmental volunteers. Journal of Environmental Planning and Management, 50(4), 503–516. https://doi.org/10.1080/09640560701402034
Burch Jr, W. R. (1979). Long distance trails. The Appalachian trail as a guide to future research and management needs. Long distance trails. Symposium on the Appalachian Trail, 11–13 October, 1977 . Yale University.
Bureau of Outdoor Recreation . (1966). Trails for America: Report on the nationwide trails study. United States Department of Interior, Bureau of Outdoor Recreation.
Cerveny, L. , Derrien, M. , & Miller, A. B. (2020). Shared stewardship and national scenic trails: Building on a legacy of partnerships. International Journal of Wilderness, 26(2), 18–33.
Cole, D. N. (1989). Recreation ecology: What we know, what geographers can contribute. The Professional Geographer, 41(2), 143–148. https://doi.org/10.1111/j.0033-0124.1989.00143.x
Cole, D. N. , Petersen, M. , & Lucas, R. C. (1987). Managing wilderness recreation use: Common problems and potential solutions. US Department of Agriculture, Forest Service, Intermountain Research Station.
Collinge, S. K. (1996). Ecological consequences of habitat fragmentation: Implications for landscape architecture and planning. Landscape and Urban Planning, 36(1), 59–77. https://doi.org/10.1016/S0169-2046(96)00341-6
Coppock, J. , & Duffield, B. (1975). Recreation in the countryside: A spatial analysis. St. Martin’s Press.
Corporation for National and Community Service . (2006). Volunteer growth in America: A review of trends since 1974. Retrieved from https://www.nationalservice.gov/pdf/06_1203_volunteer_growth.pdf
Cosgrove, I. , & Jackson, R. (1972). The geography of recreation and leisure. Hutchinson.
Eagles, P. F. , & McCool, S. F. (2002). Tourism in national parks and protected areas: Planning and management. CABI.
Fisher, R. M. , & Durrance, D. (1972). The Appalachian Trail. National Geographic Society.
Foster, C. H. (1987). The Appalachian National Scenic Trail: A time to be bold. Appalachian TrailConservancy.
Godtman Kling , K., Fredman, P. , & Wall-Reinius, S. (2017). Trails for tourism and outdoor recreation: A systematic literature review. Turizam: međunarodni znanstveno-stručni časopis, 65(4), 488–508.
Hammitt, W. E. , Cole, D. N. , & Monz, C. A. (2015). Wildland recreation: Ecology and management. John Wiley & Sons.
King, B. (2000). Trail years. In R. Rubin (Ed.). Special 75th Anniversary Issue, July 2000 – Appalachian
Trailway News (pp. 2–16, 52–63). Appalachian Trail Conservancy.
Lavery, P. (1974). Recreational geography. David and Charles.
Lavery, P. (1975). The demand for recreation: A review of studies. The Town Planning Review, 46(2), 185–200. https://www.jstor.org/stable/40103100
Leonard, R. (1979). Protecting the long trail resource: A problem analysis. In W. R. Burch Jr , (Ed.), Long distance trails. The Appalachian trail as a guide to future research and management needs. Long distance trails. Symposium on the Appalachian Trail, 11–13 October, 1977 (pp. 84–102). Yale University.
MacKaye, B. (1921). An Appalachian trail: A project in regional planning. American Institute of Architects, 9(October), 325–330.
Manning, R. E. (1979). Impacts of recreation on riparian soils and vegetation. Journal of the American Water Resources Association, 15, 30–43. https://doi.org/10.1111/j.1752-1688.1979.tb00287.x
Marion, J. L. , & Leung, Y. F. (2004). Environmentally sustainable trail management. In R. Buckley (Ed.), Environmental impacts of tourism (pp. 229–244). CABI.
Martinez, T. A. , & McMullin, S. L. (2004). Factors affecting decisions to volunteer in nongovernmental organizations. Environment and Behavior, 36(1), 112–126. https://doi.org/10.1177/0013916503256642
Massachusetts AT Committee , Massachusetts Department of Conservation and Recreation, and the Appalachian Trail Conservancy. (2019). Local management plan for the Appalachian trail in Massachusetts.Berkshire Chapter, Appalachian Mountain Club, AT Committee. On file.
Massachusetts AT Committee . (2020). Report at the 2019 Mass AT volunteer gathering. Massachusetts AT Committee.
McArdle, K. (2020). Multiple case study of nonprofit partnerships in North Carolina’s coastal state parks. Coastal Management, 48(1), 38–56. https://doi.org/10.1080/08920753.2020.1694474
Mittlefehldt, S. (2010). The people’s path: Conflict and cooperation in the acquisition of the Appalachian Trail. Environmental History, 15(4), 643–669. https://www.jstor.org/stable/25764487
Mittlefehldt, S. (2013). Tangled roots: The Appalachian Trail and American environmental politics. University of Washington Press.
Musick, M. A. , & Wilson, J. (2007). Volunteers: A social profile. Indiana University Press.
National Park Service . (2015). Foundation document, USDI, NPS. Retrieved from https://www.nps.gov/appa/getinvolved/upload/APPA-Foundation-Document-2015.pdf
Okun, M. A. , & Schultz, A. (2003). Age and motives for volunteering: Testing hypotheses derived from socioemotional selectivity theory. Psychology and Aging, 18(2), 231. https://doi.org/10.1037/0882-7974.18.2.231
Taylor, D. E. , Paul, S. , & McCoy, E. (2019). Diversity, equity, and inclusion and the salience of publicly disclosing demographic data in American environmental nonprofits. Sustainability, 11(19), 5491. https://doi.org/10.3390/su11195491
Timothy, D. J. , & Boyd, S. W. (2015). Tourism and trails: Cultural, ecological and management issues (Vol. 64). Channel View Publications.
Trauntvein, N. (2011). Volunteerism at urban park and recreation agencies: Examining the role of volunteers’ socio-demographic characteristics, motivations, organizational identity, and satisfaction on volunteer participation outcomes. [Unpublished doctoral dissertation], University of Pennsylvania.
Ward-Perkins, D. , Beckmann, C. , & Ellis, J. (2019). Tourism routes and trails: Theory and practice. CABI.
Waterman, L. , & Waterman, G. (2019). Forest and crag: A history of hiking, trail blazing, and adventure in the Northeast Mountains. SUNY Press.
Willems, J. , & Dury, S. (2017). Reasons for not volunteering: Overcoming boundaries to attract volunteers.
The Service Industries Journal, 37(11–12), 726–745. https://doi.org/10.1080/02642069.2017.1318381
World Tourism Organization . (2019). Walking tourism – Promoting regional development, UNWTO, Madrid. https://doi.org/10.18111/9789284420346.1
Wright, R. G. (1996). National parks and protected areas: Their role in environmental protection. Blackwell Science Ltd.
Yahner, T. G. , Korostoff, N. , Johnson, T. P. , Battaglia, A. M. , & Jones, D. R. (1995). Cultural landscapes and landscape ecology in contemporary greenway planning, design and management: A case study. Landscape and Urban Planning, 33(1–3), 295–316. https://doi.org/10.1016/0169-2046(94)02024-A