with whom The Chief Justice, Mr. Justice Blackmun, and Mr. Justice Rehnquist join, dissenting.
Trial and conviction in this case were in the United States District Court for the Southern District of California under an indictment charging that petitioner, contrary to 21 U. S. C. § 176a (1964 ed.), had knowingly received, concealed, and facilitated the transportation of approximately 161 pounds of illegally imported marihuana. He was sentenced to five years’ imprisonment. He appealed on the sole ground that the District Court had erroneously denied his motion to suppress marihuana allegedly seized from his automobile in violation of the Fourth Amendment.
The motion to suppress was heard on stipulated evidence in the District Court.1 United States Border Patrol Officers Shaw and Carrasco stopped petitioner’s car shortly after midnight as it was traveling from Calexico, on the California-Mexico border, toward Blythe, Cali*286fornia. The stop was made on Highway 78 near Glamis, California, 50 miles by road from Calexico. The highway was “about the only north-south road in California coming from the Mexican border that does not have an established checkpoint.” 2 Because of that, “it is commonly used to evade check points by both marijuana and alien smugglers.” On occasions “but not at all times,” officers of the Border Patrol “maintain a roving check of vehicles and persons on that particular highway.” Pursuant to this practice “they stopped this vehicle for the specific purpose of checking for aliens.” Petitioner's identification revealed that he was a resident of Mexicali, Mexico, but that he held a work permit for the United States. Petitioner had come from Mexicali, had picked up the car in Calexico and was on his way to Blythe to deliver it. He intended to return to Mexicali by bus.3 The . officers had been advised by an official bulletin that aliens illegally entering the United States sometimes concealed themselves by sitting upright behind the back seat rest of a car, with their legs folded under the back seat from which the springs had been removed. While looking under the rear seat of petitioner’s car for aliens, the officers discovered packages believed by them to contain marihuana. Petitioner was placed under arrest and advised of his rights. His ear was then searched for additional marihuana, which was found in substantial amounts.
On this evidence, the motion to suppress was denied, *287and petitioner was convicted. A divided Court of Appeals affirmed, 452 F. 2d 459 (CA9 1971), relying on its prior cases and on § 287 (a) (3) of the Immigration and Nationality Act, 8 U. S. C. § 1357 (a)(3), which provides that officers of the Immigration and Naturalization Service shall have the power, without warrant, to search any vehicle for aliens within a reasonable distance from any external boundary of the United States.4 I dissent from the reversal of this judgment.
I
The Fourth Amendment protects the people “in their persons, houses, papers, and effects, against unreasonable searches and seizures” and also provides that “no Warrants shall issue, but upon probable cause . . . .” The ordinary rule is that to be reasonable under the Amendment a search must be authorized by warrant issued by a magistrate upon a showing of probable cause. The *288Amendment’s overriding prohibition is nevertheless against “unreasonable” searches and seizures; and the legality of searching, without warrant and without probable cause, individuals and conveyances seeking to enter the country has been recognized by Congress and the courts since the very beginning. Boyd v. United States, 116 U. S. 616 (1886), said as much; and in Carroll v. United States, 267 U. S. 132, 154 (1925), the Court repeated that neither warrant nor probable cause was required to authorize a stop and search at the external boundaries of the United States: “Travelers may be so stopped in crossing an international boundary because of national self protection reasonably requiring one entering the country to identify himself as entitled to come in, and his belongings as effects which may be lawfully brought in.” This much is undisputed in this case. Persons and their effects may be searched at the border for dutiable articles or contraband. Conveyances may be searched for the same purposes, as well as to determine whether they carry aliens not entitled to enter the country. Neither, apparently, is it disputed that war-rantless searches for aliens without probable cause may be made at fixed checkpoints away from the border.
The problem in this case centers on the roving patrol operating away from, but near, the border. These patrols may search for aliens without a warrant if there is probable cause to believe that the vehicle searched is carrying aliens illegally into the country. But without probable cause, the majority holds the search unreasonable, although at least one Justice, Mr. Justice Powell, would uphold searches by roving patrols if authorized by an area warrant issued on less than probable cause in the traditional sense. I agree with Mr. Justice Powell that such a warrant so issued would satisfy the Fourth Amendment, and I would expect that such warrants would be readily issued. But I disagree with him *289and the majority that either a warrant or probable cause is required in the circumstances of this case. As the Court has reaffirmed today in Cady v. Dombrowski, post, p. 433, the governing standard under the Fourth Amendment is reasonableness, and in my view, that standard is sufficiently flexible to authorize the search involved in this case.
In Terry v. Ohio, 392 U. S. 1 (1968), the Court proceeding under the “general proscription against unreasonable searches and seizures,” id., at 20 (footnote omitted), weighed the governmental interest claimed to justify the official intrusion against the constitutionally protected interest of the private citizen. Id., at 20-21. The “ 'need to search’ ” was balanced “ 'against the invasion which the search . . . entails,’ ” quoting from Camara v. Municipal Court, 387 U. S. 523, 534-535, 536-537 (1967). Terry, supra, at 21. In any event, as put by Mr. Chief Justice Warren, the “question is whether in all the circumstances of this on-the-street encounter, his right to personal security was violated by an unreasonable search and seizure.” Id., at 9 (emphasis added).
Warrantless but probable-cause searches of the person and immediate surroundings have been deemed reasonable when incident to arrest, see Chimel v. California, 395 U. S. 752 (1969); and in Terry, the stop of a suspected individual and a pat-down for weapons without a warrant were thought reasonable on less than traditional probable cause. In Camara v. Municipal Court, supra, an inspection of every structure in an entire area to enforce the building codes was deemed reasonable under the Fourth Amendment without probable cause, or suspicion that any particular house or structure was in violation of law, although a warrant, issuable without probable cause, or reasonable suspicion of a violation, was required with respect to noneonsenting property owners. Also, in Colonnade Catering Corp. v. United *290States, 397 U. S. 72 (1970), Me. Justice Douglas, writing for the Court and recognizing that the Fourth Amendment bars only unreasonable searches and seizures, ruled that the historic power of the Government to control the liquor traffic authorized warrantless inspections of licensed premises without probable cause, or reasonable suspicion, not to check on liquor quality or conditions under which it was sold, but solely to enforce the collection of. the federal excise tax.5 United States v. Biswell, 406 U. S. 311 (1972), involved the Gun Control Act of 1968 and its authorization to federal officers to inspect firearms dealers. The public need to enforce an important regulatory program was held to justify random inspections of licensed establishments without warrant and probable cause.
The Court has been particularly sensitive to the Amendment's broad standard of “reasonableness” where, as in Biswell and Colonnade, authorizing statutes permitted the challenged searches. We noted in Colonnade that “Congress has broad power to design such powers of inspection under the liquor laws as it deems necessary *291to meet the evils at hand,” 397 U. S., at 76; and in Biswell we relied heavily upon the congressional judgment that the authorized inspection procedures played an important part in the regulatory system. 406 U. S., at 315-317. In the case before us, 8 U. S. C. § 1357 (a)(3), authorizes Border Patrol officers, without warrant, to search any vehicle for aliens “within a reasonable distance from any external boundary of the United States” and within the distance of 25 miles from such external boundary to have access to private lands, but not dwellings “for the purpose of patrolling the border to prevent the illegal entry of aliens into the United States . . . .” At the very least, this statute represents the considered judgment of Congress that proper enforcement of the immigration laws requires random searches of vehicles without warrant or probable cause within a reasonable distance of the international borders of the country.
It is true that “[ujntil 1875 alien migration to the United States was unrestricted.” Kleindienst v. Mandel, 408 U. S. 753, 761 (1972). But the power of the National Government to exclude aliens from the country is undoubted and sweeping. “That the government of the United States, through the action of the legislative department, can exclude aliens from its territory is a proposition which we do not think open to controversy. Jurisdiction over its own territory to that extent is an incident of every independent nation. It is a part of its independence. If it could not exclude aliens, it would be to that extent subject to the control of another power.” Chae Chan Ping v. United States, 130 U. S. 581, 603-604 (1889). “The power of Congress to exclude aliens altogether from the United States, or to prescribe the terms and conditions upon which they may come to this country, and to have its declared policy in that regard enforced exclusively ... is settled by our previous ad*292judications.” Lem Moon Sing v. United States, 158 U. S. 538, 547 (1895). See also Fong Yue Ting v. United States, 149 U. S. 698, 711 (1893); Yamataya v. Fisher, 189 U. S. 86, 97-99 (1903); United States ex rel. Turner v. Williams, 194 U. S. 279, 289-290 (1904); Oceanic Steam Navigation Co. v. Stranahan, 214 U. S. 320, 335-336 (1909); United States ex rel. Volpe v. Smith, 289 U. S. 422, 425 (1933).
Since 1875, Congress has given “almost continuous attention ... to the problems of immigration and of excludability of certain defined classes of aliens. The pattern generally has been one of increasing control . . . .” Kleindienst v. Mandel, supra, at 761-762. It was only as the illegal entry of aliens multiplied that Congress addressed itself to enforcement mechanisms. In 1917, immigration authorities were authorized to board and search all conveyances by which aliens were being brought into the United States. Act of Feb. 5, 1917, § 16, 39 Stat. 886. This basic authority, substantially unchanged, is incorporated in 8 U. S. C. § 1225 (a).
In 1946, it was represented to Congress that “[i]n the enforcement of the immigration laws it is at times desirable to stop and search vehicles within a reasonable distance from the boundaries of the United States and the legal right to do so should be conferred by law.” H. R. Rep. No. 186, 79th Cong., 1st Sess., 2 (1945). The House Committee on Immigration and Naturalization was “of the opinion that the legislation is highly desirable,” ibid., and its counterpart in the Senate, S. Rep. No. 632, 79th Cong., 1st Sess., 2 (1945), stated that “[t]here is no question but that this is a step in the right direction.” The result was express statutory authority, Act of Aug. 7, 1946, 60 Stat. 865, to conduct searches of vehicles for aliens within a reasonable distance from the border without warrant or possible cause. Moreover, in the Immigration and Nationality Act of 1952, 66 Stat. *293163, Congress permitted the entry onto private lands, excluding dwellings, within a distance of 25 miles from any external boundaries of the country “for the purpose of patrolling the border to prevent the illegal entry of aliens into the United States . . . §287 (a)(3), 66 Stat. 233.
The judgment of Congress obviously was that there are circumstances in which it is reasonably necessary, in the enforcement of the immigration laws, to search vehicles and other private property for aliens, without warrant or probable cause, and at locations other than at the border. To disagree with this legislative judgment is to invalidate 8 U. S. C. § 1357 (a) (3) in the face of the contrary opinion of Congress that its legislation comported with the standard of reasonableness of the Fourth Amendment. This I am quite unwilling to do.
The external boundaries of the United States are extensive. The Canadian border is almost 4,000 miles in length; the Mexican, almost 2,000. Surveillance is maintained over the established channels and routes of communication. But not only is inspection at regular points of entry not infallible, but it is also physically impossible to maintain continuous patrol over vast stretches of our borders. The fact is that illegal crossings at other than the legal ports of entry are numerous and recurring. If there is to be any hope, of intercepting illegal entrants and of maintaining any kind of credible deterrent, it is essential that permanent or temporary checkpoints be maintained away from the borders, and roving patrols be conducted to discover and intercept illegal entrants as they filter to the established roads and highways and attempt to move away from the border area. It is for this purpose that the Border Patrol maintained the roving patrol involved in this case and conducted random, spot checks of automobiles and other vehicular traffic.
*294The United States in this case reports that in fiscal year 1972, Border Patrol traffic checking operations located over 39,000 deportable aliens, of whom approximately 30,000 had entered the United States by illegally crossing the border at a place other than a port of entry. This was said to represent nearly 10% oí the number of such aliens located by the Border Patrol by all means throughout the United States.6
Section 1357 (a) (3) authorizes only searches for aliens and only searches of conveyances and other property. No searches of the person or for contraband are authorized by the section. The authority extended by the statute is limited to that reasonably necessary for the officer to assure himself that the vehicle or other conveyance is not carrying an alien who is illegally within this country; and more extensive searches of automobiles without probable cause are not permitted by the section. Roa-Rodriquez v. United States, 410 F. 2d 1206 (CA10 1969); see Fumagalli v. United States, 429 F. 2d 1011, 1013 (CA9 1970). Guided by the principles of Camara, Colonnade, and Biswell, I cannot but uphold the judgment of Congress that for purposes of enforcing the immigration laws it is reasonable to treat the exterior boundaries of the country as a zone, not a line, and that there are recurring circumstances in which the search of vehicular traffic without warrant and without probable cause may be reasonable under the Fourth Amendment although not carried out at the border itself.
*295This has also been the considered judgment of the three Courts of Appeals whose daily concern is the enforcement of the immigration laws along the Mexican-American border, and who, although as sensitive to constitutional commands as we are, perhaps have a better vantage point than we here on the Potomac to judge the practicalities of border-area law enforcement and the reasonableness of official searches of vehicles to enforce the immigration statutes.
The Court of Appeals for the Ninth Circuit, like other circuits, recognizes that at the border itself, persons may be stopped, identified, and searched without warrant or probable cause and their effects and conveyances likewise subjected to inspection. There seems to be no dissent on this proposition. Away from the border, persons and automobiles may be searched for narcotics or other contraband only on probable cause; but under § 1357 (a) (3), automobiles may be stopped without warrant or probable cause and a limited search for aliens carried out in those portions of the conveyance capable of concealing any illegal immigrant. This has been the consistent view of that court.
In Fumagalli v. United States, supra, Fumagalli was stopped at a checkpoint in Imperial, California, 49 miles north of the international boundary. In the course of looking in the trunk for an illegal entrant, the odor of marihuana was detected and marihuana discovered. Fumagalli contended that the trunk of the automobile could not be examined to locate an illegal entrant absent probable cause to believe that the vehicle carried such a person. The court, composed of Judges Merrill, Hufstedler, and Byrne, rejected the position, stating that “[w]hat all of these cases make clear is that probable cause is not required for an immigration search within approved limits [footnote omitted] but is generally required to sustain the legality of a search for contraband *296in a person’s automobile conducted away from the international borders. . . . Appellant has confused the two rules in his attempt to graft the probable cause standards of the narcotics cases . . . onto the rules justifying immigration inspections . . . 429 F. 2d, at 1013. Among prior cases reaffirmed was Fernandez v. United States, 321 F. 2d 283 (1963), where an automobile was stopped 18 miles north of Oceanside, California, on Highway 101 at a point 60 to 70 miles north of the Mexican border. An inspection for illegally entering aliens was conducted, narcotics were discovered and seized, and the stop and seizure were sustained under the statute. The Immigration Service, it was .noted, had been running traffic checks in this area for 31 years, many illegal entrants had been discovered there, and there were at least a dozen other such checkpoints operating along the border between the United States and Mexico.7
The Courts of Appeal for the Fifth and Tenth Circuits share the problem of enforcing the immigration laws along the Mexican-American border.- Both courts agree with the Ninth Circuit that § 1357 (a) (3) is not void and that there are recurring circumstances where, as the statute permits, a stop of an automobile without warrant or probable cause and a search of it for aliens are constitutionally permissible.
In United States v. De Leon, 462 F. 2d 170 (CA5 1972), De Leon was stopped without warrant or probable cause, *297while driving on the highway leading north of Laredo, Texas, approximately 10 miles from the Mexican border. The purpose of the stop was to inspect for illegally entering aliens. De Leon opened the trunk as he was requested to do. A false bottom in the trunk and what was thought to be an odor of marihuana were immediately noticed and some heroin was seized. Judge Wisdom, writing for himself and Judges Godbold and Eoney, concluded that:
“Stopping the automobile ten miles from the Mexican border to search for illegal aliens was reasonable. See United States v. McDaniel, [463 F. 2d 129 (CA5 1972)]; United States v. Warner, 5 Cir. 1971, 441 F. 2d 821; Marsh v. United States, 5 Cir. 1965, 344 F. 2d 317, 8 U. S. C. §§ 1225, 1357; 19 U. S. C. §§ 482, 1581, 8 C. F. R. § 287.1 [1973] ; 19 C. F. R. §§ 23.1(d), 23.11 [1972], Once the vehicle was reasonably stopped pursuant to an authorized border check the agents were empowered to search the vehicle, including the trunk, for aliens.” Id., at 171.
Similarly, United States v. McDaniel, 463 F. 2d 129 (CA5 1972), upheld a stop and an ensuing search for aliens that uncovered another crime. Judge Goldberg, with Judges Wisdom and Clark, was careful to point out, however, that the authority granted under the statute must still be exercised in a manner consistent with the standards of reasonableness of the Fourth Amendment. “Once the national frontier has been crossed, the search in question must be reasonable upon all of its facts, only one of which is the proximity of the search to an international border.” Id., at 133. This view appears to have been the law in the Fifth Circuit for many years.8
*298The Court of Appeals for the Tenth Circuit has expressed similar views. In Roa-Rodriquez, supra, the automobile was stopped in New Mexico some distance from the Mexican border, the purpose being to search for aliens. Relying on the statute, the court, speaking through Judge Breitenstein, concluded that “[i]n the circumstances the initial stop and search for aliens were proper.” Id., at 1208. However, when it was determined by the officers that there were no occupants of the car illegally in the country, whether in the trunk or elsewhere, the court held that the officers had no business examining the contents of a jacket found in the trunk. The evidence in this case was excluded. The clear rule of the circuit, however, is that conveyances may be stopped and examined for aliens without warrant or probable cause when in all the circumstances it is reasonable to do so.9
Congress itself has authorized vehicle searches at a reasonable distance from international frontiers in order to aid in the enforcement of the immigration laws. Congress has long considered such inspections constitutionally permissible under the Fourth Amendment. So, also, those courts and judges best positioned to make intelligent and sensible assessments of the requirements of reasonableness in the context of controlling illegal entries into this country have consistently and almost without dissent come to the same conclusion that is embodied in the judgment that is reversed today.10
*299II
I also think that § 1357 (a) (3) was validly applied in this case and that the search for aliens and the discovery of marihuana were not illegal under the Fourth Amendment. It was stipulated that the highway involved here was one of the few roads in California moving away from the Mexican border that did not have an established check station and that it is commonly used by aiien smugglers to evade regular checkpoints. The automobile, when stopped sometime after midnight, was 50 miles along the road from the border town of Calexico, proceeding toward Blythe, California; but as a matter of fact it appears that the point at which the car was stopped was approximately only 20 miles due north of the Mexican border. Given the large number of illegal entries across the Mexican border at other than established ports of entry, as well as the likelihood that many illegally entering aliens cross on foot and meet prearranged transportation in this country, I think that under all the circumstances the stop of petitioner’s car was reasonable, as was the search for aliens under the rear seat of the car pursuant to an official bulletin suggesting search procedures based on experience. Given a valid search of the car for aliens, it is' in no way contended that the discovery and seizure of the marihuana were contrary to law.11
I would affirm the judgment of the Court of Appeals.
The facts, except for when petitioner was stopped, are taken from the oral stipulation in open court. See App. 11-14. The time petitioner was stopped is given by the Complaint as 12:15 a. m., App. 4, while petitioner testified at trial that he was “stopped about 1:00.” 3 Tr. of Rec. 62.
West of Glamis the prevailing direction of the highway is east-west. At the point of the stop west of Glamis, the highway is only approximately 20 miles north of the border, running parallel to it. East of Glamis, the highway proceeds sharply northeast to Blythe, a distance of over 50 miles.
It appears, see App. 12, 13, that the officers were informed of these facts before initiating any search for aliens, and hence before finding any contraband.
Title 8 U. S. C. § 1357 (a) provides in pertinent part:
“Any officer or employee of the [Immigration and Naturalization] Service authorized under regulations prescribed by the Attorney General shall have power without warrant—
“(3) within a reasonable distance from any external boundary of the United States, to board and search for aliens any vessel within the territorial waters of the United States and any railway car, aircraft, conveyance, or vehicle, and within a distance of twenty-five miles from any such external boundary to have access to private lands, but not dwellings, for the purpose of patrolling the border to prevent the illegal entry of aliens into the United States
The Court of Appeals also relied on 8 CFR, § 287.1, which in relevant part provides:
“ (a) (2) Reasonable, distance. The term 'reasonable distance,’ as used in section 287 (a) (3) of the Act, means within 100 air miles from any external boundary of the United States or any shorter distance which may be fixed by the district director, or, so far as the power to board and search aircraft is concerned, any distance fixed pursuant to paragraph (b) of this section.”
In Colonnade Catering Corp. v. United States, 397 U. S. 72 (1970), the conviction was set aside because it was thought that Congress, with all the authority it had to prescribe standards of reasonableness under the Fourth Amendment, had not intended federal inspectors to use force in carrying out warrantless, non-probable-cause inspections. In dissent, The Chief Justice, joined by Justices Black and Stewart, would have sustained the search, saying: “I assume we could all agree that the search in question must be held valid, and the contraband discovered subject to seizure and forfeiture, unless (a) it is 'unreasonable’ under the Constitution or (b) it is prohibited by a statute imposing restraints apart from those in the Constitution. The majority sees no constitutional violation; I agree.” Id., at 78.
In a separate dissent Mr. Justice Black, joined by The Chief Justice and Mr. Justice Stewart, also emphasized that the ultimate test of legality under the Fourth Amendment was whether the search and seizure were reasonable. Id., at 79-81.
In fiscal year 1972, 398,000 aliens who had entered the United States without inspection were located by Immigration and Naturalization officers; and of the 39,243 deportable aliens located through traffic checking operations, about one-third, 11,586, had been assisted by smugglers. In fiscal year 1972, 2,880 such smugglers were discovered through trafile checking operations. Ninety-nine percent of all aliens illegally entering the United States by land crossed our border with Mexico.
In the Court of Appeals for the Ninth Circuit, 8 U. S. C. § 1357 (a) (3) has also been sustained in, e. g., Mienke v. United States, 452 F. 2d 1076 (1971); United States v. Marin, 444 F. 2d 86 (1971); Duprez v. United States, 435 F. 2d 1276 (1970); United States v. Sanchez-Mata, 429 F. 2d 1391 (1970); United States v. Avey, 428 F. 2d 1159 (1970); United States v. Miranda, 426 F. 2d 283 (1970); and United States v. Elder, 425 F. 2d 1002 (1970). See also Valenzuela-Garcia v. United States, 425 F. 2d 1170 (1970), and Barba-Reyes v. United States, 387 F. 2d 91 (1967).
E. g., Kelly v. United States, 197 F. 2d 162 (1962). See also United States v. Bird, 456 F. 2d 1023, 1024 (1972); Ramirez v. *298United States, 263 F. 2d 386, 387 (1959); and Haerr v. United States, 240 F. 2d 533, 535 (1957).
E. g., United States v. Anderson, 468 F. 2d 1280 (1972); and United States v. McCormick, 468 F. 2d 68 (1972).
Without having undertaken an exhaustive survey, in the 20 court of appeals cases I have noted, including the one before us, 35 different judges of the three Courts of Appeals found inspection *299of vehicles for illegal aliens without warrant or probable cause to be constitutional. Only one judge has expressed a different view.
The United States does not contend, see Tr. of Oral Arg. 29, and I do not suggest that any search of a vehicle for aliens within 100 miles of the border pursuant to 8 CFB, §287.1 would pass constitutional muster. The possible invalidity of the regulation and of 8 U. S. C. § 1357 (a)(3) in other circumstances is not at issue here.