Congress passed the Department of Transportation Act and two years later the Federal Aid to Highways Act that prohibited the use of federal funds to finance the construction of highways through public parks if a feasible and prudent alternative route exists. If no such route exists, the statutes allow the construction but only if there has been all possible planning to minimize harm. Petitioners contend that the Secretary violated these statutes by authorizing the building of a six-lane highway through a public park in Memphis, Tennessee. The proposed highway would have severed the zoo in the park from the rest of the park and a small creek, and 26 acres of the park would be destroyed. The actual path the highway was to take through the park had been approved in 1956, and in 1966 however, the Act prevented distribution of the monies until the Secretary determined the requirements of section 4(f) had been met. The Secretary affirmed the plan. Citizens (P) sued contending that the Secretary's actions were invalid with a formal finding. The Secretary issued affidavits which indicated that the Secretary had made the decision and that the decision was supportable. P's issued their own affidavits, which contradicted those of the Secretary. P's also sought to take the deposition of the former Secretary who had participated in the decision to route the highway through the park. A motion for summary judgment was granted to the Secretary, and the Court of Appeals affirmed. The Supreme Court granted certiorari.