Up until October 2007, the answer was generally no. But the NPS has apparently softened their stance. See their guidelines on "GPS activities":

https://www.nps.gov/policy/GPS_recreation_guidance.pdf

Yes, letterboxing is addressed in the policy.

The NPS controls not only national parks, but also national monuments, national battlefields, national seashores and national cemeteries, the Blue Ridge Parkway, Paramount Ranch, and quite a bit of other land. You can locate land managed by the NPS here.

Yes, they do occasionally check LbNA and Atlas Quest for rogue letterboxers. If you want your letterboxes to live long and happy lives, do not plant in any land under the jurisdiction without approval.

Some people assume that national forests are part of the National Park Service. This is not the case. They are two completely independent bureaucracies, and there are no known policies against letterboxing in national forests. For more information on distinguishing between the different agencies see How can I find out what agency manages the park and if they permit letterboxing?

Unfortunately there is no copyright on the name Audubon. Many different organizations and businesses call themselves Audubon and they are not related. Each would have a different policy. You have to use the words before and after Audubon to find the specific organization you are asking about.

This is an absolute and definite maybe. The website for the Audubon Society of Rhode Island describes a resounding "no letterboxing" policy. However, thethreecs, a member here on Atlas Quest who is currently employed by the Massachusetts Audubon says they have no statewide policy about letterboxing and each Audubon location is autonomous and some allow it while other don't.

Special note: The Caratunk Refuge in Seekonk, MA is under the jurisdiction of the RI Audubon Society and is subject to the "not allowed" policy despite its location in MA.

So ask before you plant. Rhode Island Audubon locations seem to not allow it while Massachusetts Audubon locations may or may not allow it. The policies of other states are unknown at this point.

Original source of Massachusetts policy (posted to the Premium Members Only board and therefore only accessible to premium members)
Audubon Society of Rhode Island

The short answer is to ask the park ranger, but if you want the details...

AGENCY:	PURPOSE:	BOXES ALLOWED?	POLICY:	LOCATION OF LAND:
FEDERAL AGENCIES:
Deptartment of the Interior:
Bureau of Land Management	To manage range lands for use by mining, grazing, oil, and gas development.	Y	Geocaching FAQsGeocaching on Public Land	Locations
Fish and Wildlife Services	To administer a national network of lands and waters for conservation.	Y - with permission only	FWS Recreational Geocaching Guidance	Locations
National Park Service	To provide use of parks for people & preserve the land in its original state.	Y - with permission only	GPS Recreation Guidance	Locations
Department of Agriculture:
Forest Service	To provide for the use of national forest resources including recreation, wildlife, wilderness, timber, mining, grazing, oil, gas, hunting, and fishing.	Y - permit required	R8 Geocaching Supplement	Locations
ALL DEPARTMENTS:
Wilderness Act of 1964	This act required all federal land agencies to set aside land designated as "wilderness areas".	N	The Wilderness Act of 1964	Locations
STATE AGENCIES:
Department of Environment and Natural Resources:
State Parks and Recreation	To preserve and protect state natural resources, including recreational activities from aquariums to zoological parks.	Depends on each state policy	See individual state policies	See state DENR
LOCAL AGENCIES:
County Parks	Overseeing local stewardship services, aquatics division, fitness and wellness, park planning, and park services.	Depends on each county policy	See individual county policies	See county website

OTHER RESOURCES:
The Wilderness Preservation System Geocaching Toolbox

NOTE:
The information here is accurate as of 8/8/2024, but policies can change. As a general rule, it is up to the individual land manager to decide and even divisions like the BLM that are generally friendly toward the hobby have the right to stop or restrict activities under Title 43 CFR section 8364.1 (a). Also, remember that within BLM and other agencies' lands, there may be areas under the wilderness designation that would prohibit letterboxing.

The policy is for caches, but the guidelines for letterboxes should be the same. They are permitted in the park but must follow guidelines (see link below):

http://www.pc.gc.ca/docs/pc/guide/geocache/geocache1_e.asp

Date of Approval: September 2007

The Nature Conservancy does not have a national policy on letterboxing. Each state and preserve may have different policies or no policy. Check with the state office to see what the situation is with an individual preserve.

In N FL, the answer is an emphatic no. This is apparently due to a bad experience with geocaches being placed without permission and the visitors trampling a lot of vegetation off-trail while searching for them.

Caching Now, an online geocaching magazine (http://www.cachingnow.com), presented a report in January 2008. In it, they presented Instruction Memorandum No. 2005-092 which is copied below. Letterboxing is not mentioned, but it's a reasonable presumption that the same guidelines that apply for geocaching would apply for letterboxing as well.

***************

UNITED STATES DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT
WASHINGTON, D.C. 20240

March 3, 2005

EMS TRANSMISSION 03/08/2005
Instruction Memorandum No. 2005-092

To: All Washington Office and Field Officials
From: Group Manager, National Recreation Group
Subject: Geocaching Activities on Bureau of Land Management (BLM) Public Lands

Program Area: Permits for Recreation of Public Lands

Purpose: This Instruction Memorandum (IM) provides general guidance for geocaching activities on BLM managed public lands.

Background: Geocaching is an outdoor adventure game for global positioning system (GPS) users. Participating in a cache hunt is an activity designed to take advantage of the features and capability of a GPS unit and enjoy the freedom of access to public land. Individuals and organizations set up caches all over the world and share the locations of these caches on the internet. GPS users use the location coordinates to find the caches. Once found, a cache may provide the visitor with a variety of awards. The visitor is asked to sign a logbook and to leave or replace items they find in the cache. The cache itself is a small waterproof box.

The general website for geocaching is www.geocaching.com. When you enter this website you can type in your zip code and see all the cache sites in your area along with the site’s latitude, longitude, a narrative description of the site location, the contents of the cache, and sometimes a map. The site also contains listings of new events and activities such as “Cache In, Trash Out” events. Geocaching provides an opportunity to hone orienteering skills, provides the opportunity to get outdoors, and it can be a wholesome family activity. It can also be conducted with minimal impact to the environment when conscientious land use ethics are followed. Even though geocaching appears to be an acceptable activity on BLM managed land, it is an activity that would only be welcome in appropriate locations.

Policy/Action: A special recreation permit (SRP) is not required if the geocaching activity complies with casual use conditions. The following conditions apply to casual use: the activity is not a commercial endeavor, the activity complies with land use decisions and designations, (i.e., special area designations and wilderness interim management policy), and it does not award cash prizes, is not publicly advertised, poses minimal risk for damage to public land or related water resource values, and generally requires no monitoring. If you determine the use to be casual but have some concern about the use, such as, placing the caches in Congressionally designated wilderness or wilderness study areas, at cultural resource sites, the areas with threatened or endangered species, or any other special fragile area, it would be appropriate to issue a “letter of agreement” with special stipulations attached that would address those concerns.

If the geocaching activity or event does not meet the above conditions, the event should be treated as any other organized recreational group or competitive activity or event for which BLM would require the event organizer to obtain an SRP.

The BLM believes that geocaching is an appropriate casual use of public land, but, as use increases or becomes a management issue in a particular area, the following minimum steps should be taken: 1) try to locate a person or group that is responsible for the cache and have them register the cache with the BLM. Make sure the cache is safe and environmentally sound, 2) prepare an environmental assessment or other appropriate National Environmental Protection Act document, 3) issue a letter of agreement or SRP with special stipulations to mitigate concerns, 4) if sites are not registered within a reasonable amount of time after notification, then the cache should be removed from public land, normally, the cache would be determined to be abandoned property after 10 days unless the appropriate authorization has been obtained, 5) monitor the use to assess public health and safety and environmental protection issues, 6) if the activity/sport becomes too large and begins to conflict with other authorized use, appropriate steps should be taken to properly manage the activity.

Time Frame: This IM is effective up receipt.

Budget Impact: This IM established general guidance on managing geocaching activities. It is expected that most of the activity would be treated as casual use on BLM managed public land, which would not require the issuance of a permit thus lessening the recreation permit workload. Therefore, the impact on the budget should be minimal.

Manual/Handbook: This policy is in conformance with the new 2930-1 manual and handbook.

Coordination: The contents of this IM has been coordinated through WO-170, The National Landscape Conservation System, BLM State Office Recreation Program Leads; WO-370, National Law Enforcement Office; and WO-240, Cultural Heritage and Paleontology Office.

Contact: If you have any questions, please contact Lee V. Larson at (202) 452-5168.

Signed by: Authenticated by:
Robert T. Ratcliffe Barbara J. Brown
Group Manager Policy & Records Group, WO-560
National Recreation Group

Individual sites may have their own permits. Allowed, provided the box/cache does not conflict with project missions or security. Containers should be clearly identified as such when placed on public lands. Transparent containers are required, due to homeland security issues. Caches should not contain alcohol, illicit, or other inappropriate materials. Information needed from the proposed geocache owner will include the location, his/her name, and his/her address and phone number. The intent of collecting this information is to keep track of the location and number of caches on the project and to contact the owner if the cache needs to be removed.

This policy on geocaching is an indication of how letterboxing can be approached.

Letterboxes are prohibited on national wildlife refuges, and they will cite you for Abandonment of property.