In this case, plaintiff Glen Zumwalt brought this action against the defendant United States "to recover for his personal injuries sustained when he fell while visiting Pinnacles National Monument in California." The facts of the case were as follows:

Pinnacles National Monument is located on 16,000 acres of land approximately 90 miles south of San Francisco Bay. Around 200,000 people visit the Monument each year. The rock pinnacles, for which the Monument is named, are remnants of a volcano that erupted 23 million years ago. Within the Monument are Talus caves formed by large boulders that have fallen into a narrow canyon. The Monument is operated by the National Park Service (NPS) and has been designated as a wilderness area under the Wilderness Act, 16 U.S.C. § 1131 et seq. A two-mile segment of the Monument's 35 miles of trails is called the Balconies Trail which passes through the Balconies Caves. Along the trail are twenty markers which are only numbers that correspond to the point of scenic interest described in a NPS pamphlet "The Balconies Self-Guiding Trail." The pamphlet also warns about special attention needed in the cave section of the trail. (The evidence of record does not show whether or not Zumwalt and his family obtained a copy of the pamphlet before the accident or even if the pamphlet was available to them on the day of the accident.)

Zumwalt, his wife and two sons arrived at the Monument around 5:00 p.m. on July 10, 1985. They intended to find a view described in a tourist guide where one could see beyond the coastal range to the San Joaquin Valley and high Sierras. While hiking along the Balconies trail, Zumwalt and his family at some point became uncertain as what way the trail continued. Seeing footprints to his left, Zumwalt went ahead of his family to check out this possible route. Zumwalt called back to his family to come ahead as this way appeared fine. While waiting for his family to catch up, Zumwalt looked around and saw a large shadowed area a few steps to his right. Wondering if it was the cave or just an alcove, Zumwalt reached and stepped into the shadowed area and fell when his foot slid on the gravel. Zumwalt was severely and permanently injured in this tragic accident.

Zumwalt fell near Marker 13. Except for the numbered markers and signs at the cave entrance indicating the need for flashlights, the trail is not otherwise marked. After Zumwalt's fall, the Safety Committee at the Monument recommended to the superintendent that hand rails be installed along the trail near Marker 13. The Safety Committee's minutes from three meetings reflect:

September 30, 1985 - New Business: ... Balconies Cave Railings (Clarence) Once railing is in place. The other needs welding. There is one place where the rock steps are small and this rail would span a dropoff - it will require careful engineering to avoid being a hazard in itself. The committee will have the next safety meeting on the westside and will observe this problem.

October 28, 1985 - Old Business: ... The safety committee decided to have the left hand railing eliminated leading up the stairs on the Balconies Caves and to install two short directional railings along the left approach to the stairs. Rocks will be placed to prevent hikers from going off the trail at the base of the right hand railing. Clarence will write a report on this for the Superintendent's approval.

November 25, 1988 - Old Business: ... Balconies Cave - Superintendent has given written approval of the committee's recommendation to use a right directional railing on the stairs. The left approach railing still needs to be split into short sections. The opening at the base of the right railing has been blocked with rocks.

The Wilderness Act federal agencies were directed "to administer wilderness areas in a manner which would preserve their 'wilderness character'." Federal law defined a wilderness area as follows:

A wilderness, in contrast with those areas where man and his own works dominate the landscape, is hereby recognized as an area where the earth and community of life are untrammeled by man, where man himself is a visitor who does not remain. An area of wilderness is further defined to mean... an area of undeveloped Federal land retaining its primeval character and influence, without permanent improvements or human habitation, which is protected and managed so as to preserve its natural conditions.

Pursuant to the Wilderness Act, the Secretary of Interior had "promulgated regulations and established management policies on wilderness preservation and management." Further, in 1983, "the Superintendent of the Monument adopted a revised 'Natural and Cultural Resources Management Plan' to guide park managers in achieving the resources management goals and objectives expressed in earlier plans." In addition, the 1983 Plan "addresses the problem of trail maintenance through Balconies Caves, discusses available alternatives, and concludes that actions would be held to a minimum 'using native material and concrete for those sections of the trail that have proven to be hazardous or difficult to follow'."

Included in the 1983 Plan was a project statement on improving the Balconies Cave Trail. It identified the problem of visitor injuries in those places where turns were missed and the visitors later suffered falls. The statement summarized current efforts to reduce injuries as additional warnings on signs and in park brochures, but that "injury and complaint levels are still unacceptably high." Alternative actions were discussed including a paved trail, additional lighting, no action, closing the cave, and upgrading hazardous portions of the trail. The action recommended was:

Since the cave is in a wilderness area, management actions will be held to a minimum. Visitor safety will be improved by using native material and concrete for those sections of the trail that have proven to be hazardous or difficult to follow.

In its discussion of the recommended alternative, the project statement included the following remark: "The location and type of improvements will be dictated by wilderness policy and the need to provide for public safety."

Zumwalt alleged that the United States "negligently maintained, managed, controlled, operated and inspected the Monument." Based upon the facts of this case, the United States denied any liability and moved for summary judgment. Specifically, the United States argued that "the alleged negligent acts of the National Park Service fall within the discretionary function exception of the FTCA [Federal Tort Claims Act]."

As described by the federal district court, the discretionary function exception of the FTCA (28 U.S.C. § 2680a) provides that the United States does not waive its sovereign immunity under the following circumstances:

Any claim based upon an act or omission of an employee of the Government, exercising due care, in the execution of a statute or regulation, whether or not such statute or regulation be valid, or based upon the exercise or performance or the failure to exercise or perform a discretionary function or duty on the part of a federal agency or an employee of the Government, whether or not the discretion involved be abused.

As noted by the federal district court, the United States Supreme Court has admitted that "its reading of the FTCA had not followed a straight line and... that it was impossible to define with precision every contour of the discretionary function exception." As described by the court, the Supreme Court has provided the following description of general principles governing the availability of governmental immunity under the discretionary function exception to the FTCA:

[T]he discretionary function or duty that cannot form a basis for suit under the Tort Claims Act includes more than the initiation of programs and activities. It also includes determinations made by executives or administrators in establishing plans, specifications or schedules of operations. Where there is room for policy judgment and decision there is discretion...

When an agency determines the extent to which it will supervise safety procedures of private individuals, it is exercising discretionary regulatory authority of the most basic kind. Decisions as to the manner of enforcing regulations directly affect the feasibility and practicality of the government's regulatory program; such decisions require the agency to establish priorities for the accomplishment of its policy objectives by balancing the objectives sought to be obtained against such practical considerations as staffing and funding... Judicial intervention in such decisionmaking through private suits would require the courts to "second-guess" the political, social, and economic judgments of an agency exercising its regulatory function. It was precisely this sort of judicial intervention in policy-making that the discretionary function was designed to prevent...

In applying the discretionary function exception, it is the nature of the conduct, instead of the status of the government agent, which controls. The choice or discretion exercised must be of the kind that Congress designed to shield with this exception.

As described by the federal district court, the United States Supreme Court has "enunciated a two step process for assessing whether the discretionary function applies" as follows:

First, the nature of the challenged conduct is examined to determine whether the government employee had any discretion or choice in his actions... Thus, the discretionary function exception will not apply when a federal statute, regulation, or policy specifically prescribes a course of action for an employee to follow. In this event, the employee has no rightful option but to adhere to the directive. And if the employee's conduct cannot appropriately be the product of judgment or choice, then there is no discretionary function exception to protect...

The second step is concerned with the particular nature of the discretion, and the court must determine whether it is the kind that Congress designed the exception to protect... Congress wished to prevent tort actions from becoming an opportunity for the courts to second guess governmental decisions grounded in social, economic and political policy.

Under the circumstances of this case, the United States argued that Zumwalt's following allegations of negligence "involve the exercise of discretion and demand a policy judgment made from balancing the often competing interests of public safety and the preservation of a wilderness area":

(1) Failure to warn Zumwalt of the potential hazard of mistaking the trail or pathway. (2) Using a ground surface on the correct path of the trail that appeared to be the same color and texture of the rest of the ground surface, making it impossible for Zumwalt to ascertain the correct and safe course of the trail. (3) Failing to use barriers, rails, signs, warnings or any other devices that would have precluded Zumwalt from inadvertently venturing into a hazardous area. (4) Failure to have adequate employees on the premises of Pinnacles National Monument to safely direct and guide patrons to the proper path or trails. (5) Failure to properly inspect the premises and take action to correct potential hazardous conditions prior to injuries occurring.

Zumwalt responded that "the only policy judgments involved are embodied in the Plan and the NPS has negligently failed to carry out that express policy." The United States, however, maintained that "its actions violated no statute, regulations, policy or other directive."

As described by the federal district court, the following "overview of the NPS and its administration of Pinnacles Monument clearly demonstrates the exercise of policy judgments in each of the government's actions which Zumwalt has alleged as negligence."

The need for additional warnings, permanent trails, additional personnel, or barriers were explicitly or implicitly considered in developing the project statement discussed above. The project statement itself shows the Superintendent's balancing of such policy factors as the preservation of the wilderness character and visitor safety. This statement also indicates that the recommended action of further improvements of hazardous portions of the trail involved the exercise of additional discretion as to need and type. The project statement does not specifically identify what portions of the trail are hazardous, and nor does it define what constitutes hazardous. These matters were left to the discretion of the safety committee to evaluate considering the overriding goal of maintaining a wilderness area, the minimum tool policy, the visitor's acceptance of the wilderness on its own terms, and visitor safety...

Both the 1983 Plan and the project statement undeniably give park personnel the room to exercise individual judgment and to balance the relevant policy factors in suggesting and carrying out safety improvements. In not making prior improvements to the trail where Zumwalt was injured, the Safety Committee and park personnel ostensibly had not identified that portion of the trail to be so hazardous as to require altering the wilderness character of the trail. The prior accident reports submitted by Zumwalt do not establish that this portion of the trail was necessarily "hazardous." Even assuming Zumwalt had succeeded in proving this, he would still have to show that NPS failed to perform a responsibility imposed by policy or regulation which did not involve the exercise of individual policy judgments.

The federal district court, therefore, concluded that exercising jurisdiction over this case "would necessitate the type of judicial 'second-guessing' of policy judgments that Congress designed the discretionary function exception to prevent." As a result, having found the record in this case "replete with proof that NPS's alleged negligent acts involved the exercise of policy judgment," the court granted summary judgment in favor of the defendant United States.