# Mammoth Cave National Park.
**AGENCY:**
National Park Service, Interior.
**ACTION:**
Proposed rule.
**SUMMARY:**
The National Park Service (NPS) proposes to amend the special regulations for Mammoth Cave National Park to allow bicycle use on approximately 37 miles of multi-use trails throughout the park. The proposed rule also would allow visitors to ride horses on the 5.4-mile Houchin Ferry North/Ollie Road.
**DATES:**
Comments on the proposed rule must be received by 11:59 p.m. eastern time on April 10, 2026.
**ADDRESSES:**
*Written Comments:* You may submit comments by one of the following methods:
(1) *Electronically:* Go to the Federal eRulemaking Portal: *https://www.regulations.gov.* In the Search box, enter 1024-AE93, the RIN for this rulemaking. On the resulting page, select the Dockets tab and then click on the title of the rule. Next, click the “Open for Comments” box, then click the blue “Comment” box and follow the instructions for submitting comments.
(2) *By hard copy:* Mail to: Superintendent, Mammoth Cave National Park, P.O. Box 7, Mammoth Cave, KY 42259.
*Document Availability:* The “Mammoth Cave National Park Comprehensive Land and River Trails Plan and Environmental Assessment” and the “Finding of No Significant Impact” provide information and context for this proposed rule. Both documents are available online at *https://parkplanning.nps.gov/maca* by clicking the link entitled “Develop Land and River Trail Management Plan for Mammoth Cave National Park” and then clicking the link entitled “Document List.”
*Instructions:* Comments will not be accepted by fax, email, or in any way other than those specified above. All submissions received must include the words “National Park Service” or “NPS” and must include the docket number or RIN (1024-AE93) for this rulemaking. Comments received may be posted without change to *https://www.regulations.gov,* including any personal information provided.
*Docket:* For access to the docket to view the proposed rule and comments received, go to *https://www.regulations.gov* and search for “1024-AE93.” Be sure to check the Dockets Tab, Documents Tab, and Comment Tab for possible results.
**FOR FURTHER INFORMATION CONTACT:**
Barclay Trimble, Superintendent, Mammoth Cave National Park; (202)-758-2180; *[email protected].* Individuals in the United States who are deaf, deafblind, hard of hearing, or have a speech disability may dial 711 (TTY, TDD, or TeleBraille) to access telecommunications relay services. Individuals outside the United States should use the relay services offered within their country to make international calls to the point-of-contact in the United States. In compliance with the Providing Accountability Through Transparency Act of 2023, the plain language summary of the proposal is available on *Regulations.gov* in the docket for this rulemaking.
**SUPPLEMENTARY INFORMATION:**
**Background**
**History, Establishment and Purpose of the Park**
Mammoth Cave National Park comprises more than 52,000 acres of land within Edmondson, Hart, and Barron Counties in Kentucky. Within Mammoth Cave National Park is Mammoth Cave. Named for the enormity of its subterranean vaults and the unparalleled extent of its passages, Mammoth Cave is the longest known cave system in the world with over 400 miles surveyed to date. The geologic features within the extensive cave system are the product of a unique set of conditions found nowhere else, all of which contribute to the largest, most complex, and best-known karst area in the world. Karst is a geologic term that refers to areas of irregular limestone in which erosion has produced features such as fissures, sinkholes, underground streams, sinking springs, and caverns. The land above the underground formations is characterized by rugged hills, valleys, and forests.
Congress authorized the establishment of the park in 1926, which was officially established in 1941 and added to in 1961 with the acquisition of Great Onyx Cave and Crystal Cave. The legislative history of the establishment of the park recognized the need to protect and conserve the stunning and unique underground formations of the cave system, but also opportunities for recreation that could be provided by lands above ground. The park's enabling legislation directs the NPS to administer the park in accordance with the laws generally applicable to the National Park System, including the NPS Organic Act. That act requires the NPS to promote and regulate the scenery, natural and historic objects, and wild life in parks and to provide for the enjoyment of the same in such manner and by such means that will leave them unimpaired for the enjoyment of future generations. 54 U.S.C. 100101.
In 2014, the NPS published the foundation document for the park. The document states that the park's purpose is to preserve, protect, interpret, and study the internationally recognized biological and geologic features and processes associated with the longest known cave system in the world, the park's diverse forested, karst landscape, the Green and Nolin rivers, and extensive evidence of human history; and to provide and promote public enjoyment, recreation, and understanding. Today, visitors are drawn to the park by its caves, scenic river valleys, bluffs, forests, and abundant wildlife. Above ground, the park offers opportunities for ranger-led tours, surface walks, camping, hiking, horseback riding, bicycling, scenic drives, canoeing and kayaking, fishing, accessible trails, and picnicking.
**Trail Use in the Park**
Bicycling is allowed on approximately 19 of the 85 miles of land-based trails within the park. These multi-use trails are the Connector Trail from the Big Hollow Trailhead to the Maple Springs Trailhead (Maple Springs Connector Trail), the Big Hollow Trail, the Mammoth Cave Railroad Bike & Hike Trail, and the White Oak Trail. Bicycles also are allowed on roads that are open to public motor vehicle traffic and on four administrative roads that are closed to motor vehicle use by the public but open to motor vehicle use by the NPS for administrative purposes (the Crystal Cave, Great Onyx, Three Springs, and Union City administrative roads).
Trails, public roads, and administrative roads that are open to traditional bicycles also are open to two-wheeled electric bicycles (e-bikes). Trail-use of three-wheeled e-bikes is limited to the Mammoth Cave Railroad Bike & Hike Trail and the Maple Springs Connector Trail. The use of traditional bicycles and e-bikes is governed by State law and NPS regulations that address topics such as speed limits, operation during periods of low visibility, obeying traffic control devices, and unsafe operation. See 36 CFR 4.30.
In addition to opportunities for hiking and bicycling, visitors can ride horses on 54 miles of trail within the park, featuring wooded backcountry routes suitable for different skill levels and ages. The trails include wide, smooth dirt paths that accommodate two riders as well as narrower, single-file ridgeline trails. Horseback riding is prohibited on all park roads pursuant to NPS general regulations that prohibit the use or horses on park roads except in limited circumstances. See 36 CFR 2.16.
**Comprehensive Land and River Trails Plan and Environmental Assessment**
In 2022, the NPS began developing a new land and river trails management plan for the park. The NPS initiated this planning process because previous plans had become outdated, and the condition of the park's trail system had deteriorated in a way that was adversely impacting park resources and the experience of trail users. The new plan would guide trail management for several decades with the purpose of improving access to high-quality land and river-based recreational opportunities for a diverse group of trail users, including hikers, equestrians, mountain bikers, and paddlers.
After the conclusion of a preliminary planning phase that sought feedback from trail users, community groups, and the general public, the NPS published the “Mammoth Cave National Park Comprehensive Land and River Trails Plan and Environmental Assessment” in 2024. The environmental assessment (EA) analyzed the potential environmental impacts of a no-action alternative that would have continued current management of the trail system and an action alternative that was identified as the NPS's preferred alternative. Under the action alternative, the NPS would add approximately 66 miles of land-based trails to the park trail system. This 72 percent increase in trail mileage would create new opportunities for hiking, horseback riding, and bicycling.
Specific to bicycle use, under the preferred alternative, the NPS would (1) discontinue bicycle use on the White Oak Trail; (2) close and restore to natural conditions the Maple Springs Connector Trail; and (3) construct eight new multi-use trails where bicycle use would be allowed, resulting in a total of approximately 37 miles of trail open to bicycle use.
As described in the EA, trail construction activities would use sustainable trail techniques to manage water and limit erosion, such as trail hardening, grade reversals, outslopes, and other earthwork strategies that improve drainage. These measures would minimize trail widening and trail braiding on new and rehabilitated trails, resulting in less vegetation trampling. The NPS would implement mitigation measures to minimize the impact on native vegetation during construction.
In addition to evaluating the potential impacts of trail construction and modification activities, the EA evaluated the potential impacts of allowing bicycles on the new trails. The EA and an associated written determination required by NPS regulations evaluate the suitability of trail surfaces and soil conditions for accommodating bicycle use; life cycle maintenance costs, safety considerations, methods to prevent or minimize user conflict, and methods to protect natural and cultural resources and mitigate impacts from bicycle use. Under the preferred alternative, the NPS would convert a one-mile section of the Ugly Creek Road from a public road to an administrative road that is closed to motor vehicle use other than vehicles used by the NPS for administrative purposes. Hiking and bicycling would be allowed on the converted section of this road.
The preferred alternative also would open the Houchin Ferry North/Ollie Road (5.4 miles) to horseback riding. This change would improve the experience of equestrians by providing multiple opportunities for longer loop rides, and a new opportunity to ride to the river and back from the northern boundary of the park. The NPS does not anticipate there will be conflicts between vehicles, equestrian users, hikers, and bicyclists because the road is used rarely by motor vehicles. All other public and administrative roads would continue to remain closed to equestrian use.
The NPS accepted public comments on the EA for 30 days. In December 2024, following a recommendation by the park superintendent, the Regional Director for Interior Region 2, South Atlantic—Gulf, signed a finding of no significant impact on the human environment (FONSI) that identified the preferred alternative in the EA as the selected alternative. As stated in the FONSI, the NPS believes the selected alternative will improve the conditions and sustainability of the aboveground land and water trail networks in the park and enhance the diversity and quality of visitor experiences while protecting natural and cultural resources. Implementation of the selected alternative will expand opportunities for visitors to enjoy and recreate within the park.
**Proposed Rule**
This rule would implement part of the selected alternative in the FONSI by amending the special regulations for the park in 36 CFR 7.36. This rule would authorize the superintendent to designate approximately 37 miles of multi-use trails for bicycle use in the park. The rule would identify 12 distinct trails that could be designated for bicycle use. Two trails currently designated for bicycle use—the Maple Springs Connector Trail and the White Oak Trail—would be removed, consistent with plans to close those trails to bicycle use under the selected alternative. Another currently designated trail—the Mammoth Cave Railroad Bike & Hike Trail—will remain on the list and another—the Big Hollow Trail—will be listed as three separate segments as identified on park maps.
The rule would add the following eight new trails that will be constructed under the selected alternative:
• Brooks Knob Road Cemetery Trail;
• Brooks Knob Road Trail (up to gate);
• Crystal Cave Road Trail;
• East Entrance Trail;
• Little Hope Cemetery Trail;
• Sugar Sink Connector Trail;
• Sugar Sink Trail; and
• West Entrance Trail.
The rule would include the approximate mileage of all of the identified trails. The rule would require the superintendent to notify the public of designated trails through one or more of the methods identified in 36 CFR 1.7, including publication in the superintendent's compendium (or written compilation) of discretionary actions and on maps available at the visitor center and on the park website. NPS regulations at 36 CFR 4.30(i) authorize superintendents to allow electric bicycles on park roads, parking areas, and administrative roads and trails that are otherwise open to traditional bicycles. Accordingly, the superintendent may decide to allow electric bicycles on any of the trails identified in the rule that are open to traditional bicycles and will notify the public pursuant to 36 CFR 1.7.
NPS general regulations in 36 CFR 2.16(c) prohibit the use of horses or pack animals on a park road, except where such travel is necessary to cross to or from designated trails, areas, or privately owned property when no alternative trails or routes have been designated, and when the road is closed to motor vehicles. Neither of these exceptions to the general rule apply to riding horses on the Houchin Ferry North/Ollie Road, which is called for in the selected alternative. Special regulations for the park, however, can amend, modify, relax, or make more stringent general regulations in 36 CFR parts 1 through 5 and part 12. See 36 CFR 1.2(c). Accordingly, this rule would add a new paragraph (d) to the special regulations for the park that would allow equestrian use on the approximately 5.4-mile Houchin Ferry North/Ollie Road.
**Compliance With NPS Bicycle Regulations**
The EA constitutes the planning document and evaluates the criteria required by the NPS's general bicycle regulations at 36 CFR 4.30. Under the selected action in the FONSI, the NPS would allow bicycle use on approximately 37 miles of multi-use trails in the park. The EA evaluates the suitability of each trail surface and soil conditions for accommodating bicycle use; and life cycle maintenance costs, safety considerations, methods to prevent or minimize user conflict, and methods to protect natural and cultural resources and mitigate impacts associated with bicycle use.
The final trail alignments shown on the maps in the EA are based on field surveys and geographic information system (GIS) analysis. The new trail alignments have been determined at the corridor level, defined as a 60-foot-wide corridor within which the new trail would be constructed. Final trail alignments would be determined on the ground upon implementation and in consultation with park natural and cultural resources specialists, which could result in minor adjustments to the trail locations shown on the maps. If a need existed to align a trail outside of the identified corridor, the amended alignment would undergo additional review to avoid or minimize impacts on sensitive resources, and the change would be documented as an amendment to the trails management plan.
The superintendent of the park has signed a written determination that bicycle use on all of the trails identified in this proposed rule and certain administrative roads that would be open to bicycle use under the selected action in the FONSI, is consistent with the protection of the park's natural, scenic, and aesthetic values; safety considerations; management objectives; and will not disturb wildlife or park resources, as required by 36 CFR 4.30. This written determination is available on the park's planning website at the URL listed in the *ADDRESSES* section. The NPS is not publishing the written determination separately in the *Federal Register* but welcomes comments on the written determination during the public comment period for this proposed rule.
**Compliance With Other Laws, Executive Orders and Department Policy**
**Regulatory Planning and Review (Executive Orders 12866 and 14192)**
This rule has been determined to be not significant for purposes of Executive Order (E.O.) 12866. This rule is an E.O. 14192 deregulatory action.
**Regulatory Flexibility Act (RFA)**
This proposed rule would not have a significant economic effect on a substantial number of small entities under the RFA (5 U.S.C. 601 *et seq.* ). No small entities would be directly regulated by the proposed rule, which would allow bicycle use on approximately 37 miles of multi-use trails throughout the park and allow visitors to ride horses on the 5.4-mile Houchin Ferry North/Ollie Road. This action would not impose restrictions on local businesses in the form of fees, training, record keeping, or other measures that would increase costs. Rather, this action could lead to a slight increase in park visitation and thereby generate benefits for businesses, including small entities, through increased visitor spending. Therefore, the NPS certifies that, if made final, this proposed rule would not have a significant economic impact on a substantial number of small business entities.
**Congressional Review Act**
This proposed rule, if finalized, would not be a major rule under 5 U.S.C. 804(2). This proposed rule:
(a) Would not have an annual effect on the economy of $100 million or more.
(b) Would not cause a major increase in costs or prices for consumers, individual industries, Federal, State, or local government agencies, or geographic regions.
(c) Would not have significant adverse effects on competition, employment, investment, productivity, innovation, or the ability of U.S.-based enterprises to compete with foreign-based enterprises.
**Unfunded Mandates Reform Act**
This proposed rule would not impose an unfunded mandate on State, local, or Tribal governments or the private sector of more than $100 million per year. This proposed rule would not have a significant or unique effect on State, local or Tribal governments, or the private sector. It addresses public use of national park lands and imposes no requirements on other agencies or governments. A statement containing the information required by the Unfunded Mandates Reform Act (2 U.S.C. 1531 *et seq.* ) is not required.
**Takings (E.O. 12630)**
This proposed rule would not effect a taking of private property or otherwise have takings implications under E.O. 12630. A takings implication assessment is not required.
**Federalism (E.O. 13132)**
Under the criteria in section 1 of E.O. 13132, this proposed rule would not have sufficient federalism implications to warrant the preparation of a federalism summary impact statement. This rule would only affect use of federally administered lands and waters. It would have no direct effects on other areas. A federalism summary impact statement is not required.
**Civil Justice Reform (E.O. 12988)**
This proposed rule complies with the requirements of E.O. 12988. This proposed rule:
(a) Meets the criteria of section 3(a) requiring that all regulations be reviewed to eliminate errors and ambiguity and be written to minimize litigation; and
(b) Meets the criteria of section 3(b)(2) requiring that all regulations be written in clear language and contain clear legal standards.
**Consultation With Indian Tribes (E.O. 13175 and Department Policy)**
The Department of the Interior strives to strengthen its government-to-government relationship with Indian Tribes through a commitment to consultation with Indian Tribes and recognition of their right to self-governance and sovereignty. The NPS has evaluated this proposed rule under the criteria in E.O. 13175 and under the Department's Tribal consultation policy. As a result, the NPS determined that Tribal consultation is not required because this rule, if finalized, will have no substantial direct effect on federally recognized Indian Tribes.
Nevertheless, in support of the Department of the Interior's and the NPS's commitment to government-to-government consultation, the NPS initiated Tribal consultation for the EA on April 30, 2024, by sending letters to the following Native American Tribes affiliated with lands and waters within the park and inviting consultation: Absentee Shawnee Tribe (Absentee-Shawnee Tribe of Indians of Oklahoma); The Chickasaw Nation; Cherokee Nation; Eastern Band of Cherokee Indians; Eastern Shawnee Tribe of Oklahoma; The Osage Nation; Shawnee Tribe; and United Keetoowah Band of Cherokee Indians in Oklahoma.
The NPS will continue to consult with Tribes through the rulemaking process. Additionally, the NPS developed a phased programmatic agreement to guide the treatment of cultural resources in the different project areas identified in the EA. The NPS invited each of these Tribes to sign on to the phased programmatic agreement. None chose to do so. The Cherokee Nation responded that they would consult with the NPS when there are defined undertakings for any project involving ground disturbance. No other Tribal responses were received.
**Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)**
This proposed rule contains no new information collections. All information collections require approval under the Paperwork Reduction Act of 1995 (PRA; 44 U.S.C. 3501 *et seq.* ). The NPS may not conduct or sponsor, and you are not required to respond to a collection of information unless it displays a currently valid OMB control number.
**National Environmental Policy Act of 1969 (NEPA; 42 U.S.C. 4321 et seq.)**
The NPS prepared the EA to determine whether this proposed rule would have a significant impact on the quality of the human environment under NEPA. This proposed rule would not constitute a major Federal action significantly affecting the quality of the human environment. A detailed statement under NEPA is not required because the EA resulted in FONSI. A copy of the EA and FONSI are available online at *https://parkplanning.nps.gov/maca* by clicking the link entitled “Develop Land and River Trail Management Plan for Mammoth Cave National Park” and then clicking the link entitled “Document List.”
**Effects on the Energy Supply (E.O. 13211)**
This proposed rule is not a significant energy action under the definition in E.O. 13211. The Office of Information and Regulatory Affairs (OIRA) determined this proposed rule is not significant under E.O. 12866. Consequently, this proposed rule does not meet the first criteria of a significant energy action. Also, the OIRA Administrator has not otherwise designated this proposed rule as a significant energy action. A statement of energy effects in not required.
**List of Subjects in 36 CFR Part 7**
National parks, Reporting and recordkeeping requirements.
In consideration of the foregoing, the National Park Service proposes to amend 36 CFR part 7 as set forth below:
**PART 7—SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM**
1. The authority citation for part 7 continues to read as follows:
**Authority:**
54 U.S.C. 100101, 100751, 320102; Sec. 7.96 also issued under D.C. Code 10-137 and D.C. Code 50-2201.07.
2. In § 7.36:
a. Revise paragraph (c)(1); and
b. Add new paragraph (d).
The revision and additions read as follows:
§ 7.36
(c) Bicycle Use. (1) The Superintendent may designate all or a portion of the following trails as open to bicycle use. A map showing trails open to bicycle use will be available at the park visitor center and posted on the park website, and all trails or portions of trails designated for bicycle use will be published in the Superintendent's Compendium (or written compilation) of discretionary actions referred to § 1.7(b).
(i) Big Hollow North (approximately 5.0 miles);
(ii) Big Hollow North Shortcut (approximately 0.1 miles);
(iii) Big Hollow South (approximately 3.7 miles);
(iv) Brooks Knob Road Cemetery Trail (approximately 0.4 miles);
(v) Brooks Knob Road Trail (up to gate) (approximately 0.2 miles);
(vi) Crystal Cave Road Trail (approximately 0.1 miles);
(vii) East Entrance Trail (approximately 2.8 miles);
(viii) Little Hope Cemetery Trail (approximately 0.1 miles);
(ix) Mammoth Cave Railroad Bike & Hike Trail (approximately 9.3 miles);
(x) Sugar Sink Connector (approximately 0.2. miles)
(xi) Sugar Sink Trail (approximately 3.8 miles)
(xii) West Entrance (approximately 11.2 miles)
(d) Horses. Equestrian use is allowed on Houchin Ferry North/Ollie Road (approximately 5.4 miles).
Kevin J. Lilly,
Principal Deputy Assistant Secretary, Exercising the Delegated Authority of the Assistant Secretary for Fish and Wildlife and Parks.