The California State Agricultural Labor Relations Board has promulgated a regulation providing, that the self-organization rights of employees include “the right of access by union organizers to the premises of an agricultural employer for the purpose of meeting and talking with employees and soliciting their support.” A labor organization may “take access” to an agricultural employer’s property for up to four 30-day periods in one calendar year. All a labor organization needs to do is file a written notice with the Board and serve a copy to the employer. Two organizers per work crew may enter the employer’s property for up to one hour before work, one hour during the lunch break, and one hour after work. Organizers are free to meet and talk with employees as they wish. P is a strawberry grower in northern California. It employs over 400 seasonal workers and around 100 full-time workers, none of whom live on the property. At five o’clock one morning, members of the United Farm Workers entered P’s property without prior notice. The organizers moved to the nursery’s trim shed, where hundreds of workers were preparing strawberry plants. Calling through bullhorns, the organizers disturbed operations, causing some workers to join the organizers in a protest and others to leave the worksite altogether. P filed a charge against the union for taking access without giving notice. The union alleged that P had committed an unfair labor practice. At Fowler Packing Company the United Farm Workers attempted to take access to Fowler’s property, but the company blocked them from entering. The union filed an unfair labor practice charge against Fowler, which it later withdrew. Ps filed suit in Federal District Court against several Board members in their official capacity. Ps alleged an unconstitutional per se physical taking under the Fifth and Fourteenth Amendments by appropriating without compensation an easement for union organizers to enter their property. They requested declaratory and injunctive relief prohibiting the Board from enforcing the regulation against them. The District Court granted the Board’s motion to dismiss. The court held that the access was not in a permanent and continuous manner. It deemed the regulation was subject to evaluation under the multifactor balancing test of Penn Central. The Court of Appeals for the Ninth Circuit affirmed. The court identified permanent physical invasions, regulations that deprive an owner of all economically beneficial use of his property, and the remainder of regulatory actions. The court reasoned that while regulations in the first two categories constitute per se takings, those in the third must be evaluated under Penn Central. The dissent observed that the Supreme Court had never allowed labor organizers to enter an employer’s property for substantial periods of time when its employees lived off-premises. The dissent held that the regulation constituted a physical occupation and therefore effected a per se taking. En banc dissent held that the access regulation appropriated from the growers a traditional form of private property-an easement in gross-and transferred that property to union organizers. The Supreme Court granted certiorari.