With two co-defendants, appellant Joan McCoy was tried and convicted on three counts of reentering a military installation, in violation of 18 U.S.C. § 1382, after having been ordered by the commanding officer not to reenter.1 The alleged reentries *827occurred when Mrs. McCoy stationed herself in the driveway of the main entrance of Wurtsmith Air Force Base to pass out leaflets to people entering the base. She did not interfere with anyone’s access to the base, as we infer from the record, and conducted herself in an orderly and peaceful manner at all times pertinent to our inquiry.
Sitting without a jury, the district court found the driveway to be “part of the military base_” Mrs. McCoy’s main argument on appeal is that the government failed to sustain its burden of proving that the driveway was in fact part of the base. And even if the driveway was within the confines of the base, she argues, the refusal to let her distribute leaflets there restricted the exercise of her First Amendment rights unreasonably.
Upon review, we conclude that the evidence before the trial court was sufficient to support the court’s finding that the driveway was part of the military base. That being the case, we do not believe that the Air Force had any constitutional duty to make the driveway available for the dissemination of leaflets by civilians who had been barred from the base under § 1382.
I
Wurtsmith Air Force Base (formerly Os-coda Army Air Field) is a federal military installation located in Iosco County, Michigan. The main entrance to the base is situated on the west side of a county highway known as Highway F-41.
Iosco County does not hold a fee interest in the land occupied by the highway. The County Road Commission’s Director of Surveys, called as a witness by the defendants, testified that the federal government apparently had granted a right-of-entry to the State Highway Department for construction of the highway, as had the State Conservation Department. (Certain lease agreements received in evidence suggest that the United States leases the base from the State of Michigan; the land may at one time have come within the jurisdiction of the Conservation Department.) The Highway Department subsequently relinquished its right-of-entry to the county. It is clear, as the Director of Surveys testified, that the county does not “own” the road. The Highway Department “couldn’t give us the property,” he explained, “because they didn’t own it. All they had was a highway easement release, which was a right of entry. All we have today is the same instrument.”
The government’s evidence established without contradiction that Wurtsmith Air Force Base is not an “open base.” Members of the public who wish to come on the base are supposed to request permission at a manned gatehouse located at the main entrance.
Security at the base, it would appear, has not always been perfect. In October of 1983, according to the testimony of a co-defendant, Mrs. McCoy and 16 others participated in a “public vigil” conducted on the airstrip of the base. The purpose of occupying the airstrip was to protest the deployment of missiles on the base and in Europe.
The 1983 incident resulted in Mrs. McCoy and her co-defendants receiving letters from the base commander barring them from reentering the base. The letter to Mrs. McCoy, dated 23 October 1983 and signed by her to acknowledge receipt, cited 18 U.S.C. § 1382 and ordered Mrs. McCoy not to reenter the confines of the installation without the written permission of the commander or his designee.
Mrs. McCoy received a second such letter in June of 1984. She acknowledged from the witness stand that prior to March of 1986 “I was barred twice” from entry onto Wurtsmith Air Force Base. Mrs. McCoy does not contend that there was any defect in the bar letters, or that their issuance was unreasonable or unlawful. And Mrs. McCoy could not profess ignorance of the *828law; the letters explained § 1382 to her, and the record indicates that she had a prior conviction under the statute in any event.
The first of the three acts of alleged trespass involved in the present case occurred on March 9, 1986, at a time when Mrs. McCoy and her co-defendants were engaged in what they described as “monthly leafletting” at the base. Mrs. McCoy testified that as she was passing out her leaflets on the west side of Highway F-41 in a paved area that she believed was within the public right-of-way, a person from the military approached her and informed her that she was on base property. He instructed her to leave — and, as she conceded, he gave her an opportunity to do so. She did not leave, but continued to hand out her leaflets from the spot that she had been told was base property. She was then taken into custody by military personnel.
Following this incident the Air Force decided to have a white line painted across the driveway at the main entrance to identify the boundary of the base. The line was painted by military prisoners working under the direction of a master sergeant. Instructions on where the line was to be painted “got messed up between the master sergeant and the prisoners,” according to the base operations officer, a Captain Kerby, and the prisoners did their painting in the wrong place. This happened on or about May 1, 1986, according to the testimony.
To correct the mistake, Captain Kerby had the line painted over with black paint and had a new line painted where he had been told the actual boundary was. He had intended from the beginning that the line be placed there. The correction was made on or about May 8,1986, and the new line was in place before Mrs. McCoy’s next visit.
That visit occurred on May 11, 1986, a day referred to in Mrs. McCoy’s testimony as “Mothers’ Peace Day.” Mrs. McCoy testified that on this occasion she not only saw the freshly painted line, she “straddled it” in the course of passing out leaflets for an hour and a half or more. From time to time she stepped over the line in order to avoid traffic, Mrs. McCoy said, and in handing a leaflet to the occupant of a car that was in motion, she would sometimes step over the line in her “excitement.” Asked if she “did at times go within the [base] confines,” her answer was “yes.” When asked by the court if she continued to try to do the same thing after realizing that occasionally she had to step off the line, Mrs. McCoy again answered “yes.”
It is undisputed that on May 11, as on March 9, Mrs. McCoy was asked to leave after Captain Kerby thought she had crossed the boundary of the base. Reading aloud from a prepared statement, Captain Kerby told Mrs. McCoy that she was on Wurtsmith Air Force Base without the permission of the base commander and would have to leave immediately. As on March 9, she did not leave; again she was taken into custody.
On June 8, 1986, Mrs. McCoy again stationed herself in the driveway at the entrance to the base. Again she was instructed to leave, again she was given an opportunity to step away from the area asserted to be base property, again she stood her ground, and again she was arrested. At no time, she testified, did she have any difficulty understanding the instructions to leave.
Although the legal status of the spot where Mrs. McCoy chose to pass out her leaflets is disputed, its physical position is not. The location is marked with the letter “C” on Exhibit 8, an aerial photograph that depicts Highway F-41, the gatehouse, two driveways that run between the gatehouse and the highway, and a grass-covered “island” that lies between the two driveways. The relationship of the key elements in the photograph is shown in the following diagram:
*829[[Image here]]
As indicated by the diagram, there is a turning lane on the west side of the highway for use by southbound traffic preparing to turn in at the driveway to the gatehouse. A painted line — a line that marks the boundary of the base, according to Captain Kerby — separates the turning lane from the through traffic lane. The painted boundary line did not extend across the driveway on March 9, but it did on May ll.2 Captain Kerby testified that on March 9, 1986, Mrs. McCoy was positioned in the driveway to the west of the then unextend-ed line at the point marked “C.” She has never disputed that this was the point at which she was standing on March 9. Moreover, as we have seen, she admitted that on May 11, after the line had been extended across the driveway, she knowingly stepped to the west of the line in the course of her leafletting activities. There is no controversy about her having done the same thing on June 8.
The position of the island, which was emphasized in the findings of the trial court, is of particular interest. The island extends from the gatehouse all the way to the boundary line, making it impossible for traffic heading south in the turning lane to continue to move in the same direction without turning. The island was plainly part of the base. Prominently displayed on the island was a large sign bearing the legend reproduced below:
[[Image here]]
Because the island extended all the way to the edge of the southbound traffic lane of the highway, a person standing in the driveway next to the island at the point marked “C” on the diagram would not normally have to worry about being hit by southbound traffic coming from the turning lane on the other side of the driveway. The island would also afford a person standing in that location a measure of protection from traffic moving in the through lane. It would thus be fair to say that the reason Mrs. McCoy found it safer to stand in the driveway at location “C,” with the island to the south and west of her, instead of standing two or three feet to the east, is that in the former location she would be on the base, while in the latter she would be in the southbound traffic lane of the highway.
After considering all the evidence, the district court found not only that the driveway was part of Wurtsmith Air Force Base, but that Mrs. McCoy and her two co-defendants had been ordered by the person in command not to reenter the base; that each defendant did, in fact, reenter the base on three separate occasions in three different months; that each defendant was given actual notice that she was considered to be upon a military base; and that each *830defendant nonetheless failed to leave, although afforded a reasonable opportunity to do so. On these findings the district court, in the person of Judge James P. Churchill, found each defendant guilty on three counts of violating 18 U.S.C. § 1382.
Only Mrs. McCoy has appealed. Mrs. McCoy was sentenced to serve a total of 12 weeks in prison, but Judge Churchill made it clear to her that if she wanted to exhaust her appeal rights before serving her sentence, she could do so by posting bond. Mrs. McCoy elected not to wait, and served her time before the briefs were filed in this court. It is now up to us to tell her whether she made a mistake in promptly accepting the punishment that the district court felt constrained to impose.
She made no mistake.3 Her error, if any, was in stepping over the line in the first place, not in accepting her punishment for doing so.
II
Does the driveway at the main entrance of Wurtsmith Air Force Base constitute part of a military installation, as the trial court found?
The prosecution did not prove to the satisfaction of the trial court that the United States holds a leasehold or fee interest in any of the land occupied by the base, and there was no attempt to prove that the portion of the driveway where Mrs. McCoy passed out her leaflets lay outside the right-of-way “released” for Highway F-41. No such proof was necessary, in our view.
The existence of Wurtsmith Air Force Base does not depend on the strength of the government’s legal title. Like the famous stone that Dr. Johnson kicked in refuting Bishop Berkeley, Wurtsmith Air Force Base exists. Anyone who looks at the base can see that it exists. It has existed, as the evidence showed, since World War II. It is undisputed that the government has enjoyed a possessory interest in the base for decades. The source of that interest is immaterial as far as the issue before us in this case is concerned.
If it were known that the military airstrip which was occupied by Mrs. McCoy and her fellow demonstrators in 1983 had been built on land owned outright by Iosco County, instead of on land leased from the State of Michigan by the United States, the airstrip would still have been part of a military installation possessed and operated by the United States — and it would still have been off-limits to anyone barred from the base under § 1382.4 Had it been *831shown that the driveway where Mrs. McCoy passed out her leaflets in 1986 was built on land owned by the county, similarly, the driveway would have been no less a part of the base.
But the main driveway of Wurtsmith Air Force Base was not built on land owned by the county. The county’s right-of-way may have overlapped the driveway and the adjacent island, but a mere right-of-way, as the trial court noted, “is less than owner-ship_” The typical Michigan suburbanite owns the portion of his driveway that lies between the sidewalk and the street, even though that portion of the driveway is burdened by a local government’s right-of-way. The right-of-way may cover the suburbanite’s entire tree lawn, along with such of the driveway as lies within the tree lawn, but the right-of-way is less than ownership in fee, and the driveway belongs to the homeowner. As far as Wurtsmith Air Force Base is concerned, similarly, Judge Churchill said “there isn’t any question that the entire area up to at least the center of the road, if not beyond, is a part of the military base....” As a matter of real estate law, that proposition would seem unassailable. See Loud v. Brooks, 241 Mich. 452, 217 N.W. 34 (1928).
This does not necessarily mean, of course, that Mrs. McCoy could have been convicted under § 1382 for simply driving past the base in the southbound lane of Highway F-41. See United States v. Watson, 80 F.Supp. 649 (E.D.Va.1948). See also United States v. Albertini, 472 U.S. 675, 698-99, 105 S.Ct. 2897, 2911-12, 86 L.Ed.2d 536 (1985), where Justice Stevens, writing in dissent, suggested that Congress could not have intended to impose criminal liability on a hypothetical person who, after being barred from Hickam Air Force Base, left Honolulu International Airport in a flight which used the main runway of that airport, a portion of which runway lies inside Hickam. “The use of these military lands for the limited public purposes for which they have been set aside,” Justice Stevens wrote, “does not involve the bold defiance of authority that is foreseen by the structure of the statute and reflected in its legislative history.”
But the authorities at Wurtsmith Air Force Base made no attempt to prevent Mrs. McCoy from using the southbound traffic lane of Highway F-41 for the limited public purpose for which it had been set aside. On the contrary, they caused a line to be painted at the point where the driveway of the base meets the through traffic lane, and they told Mrs. McCoy, in effect, that she was free to go thus far, but no farther. The driveway area west of the boundary line had not been set aside as a public forum, and Mrs. McCoy’s insistence on crossing the line to use the driveway for that purpose involved precisely the sort of “bold defiance of authority” that was missing in Justice Stevens’ hypothetical airline passenger case.
From a political or religious standpoint, Mrs. McCoy’s defiance of authority may seem wholly admirable — and even people who disagree with the view that world peace would be enhanced if the United States gave up its nuclear arms can admire the spirit that Mrs. McCoy displayed in defying an authority she considers misguided. But it seems obvious to us from a legal standpoint, as it seemed obvious to Judge Churchill, that when Mrs. McCoy chose to cross the line separating the through traffic lane from the entrance to the military installation, she chose to break the law.
The case at bar presents, in many ways, a mirror image of the factual situation in United States v. Parrilla Bonilla, 648 F.2d 1373 (1st Cir.1981). The defendants in that case entered upon a U.S. Navy installation’s beach in an area where there was *832no “visible boundary marking from which to infer the Navy’s closing of the installation to outsiders.” Id. at 1378. Here, by contrast, the Air Force put down a clearly visible boundary marking so that there could be no possible doubt that the area west of the line was closed to outsiders. The message conveyed by the line was reinforced, as far as Mrs. McCoy was concerned, by Air Force personnel telling her to her face that “[y]ou are on a United States military reservation,” and “you are hereby ordered to leave.” If the government was required to show knowledge by Mrs. McCoy that her entry “was, in fact, prohibited,” see Parrilla Bonilla, 648 F.2d at 1377, we are certainly in no position to quarrel with Judge Churchill’s findings that the driveway area was “within the control of the military” and that “[anybody has to have their head in the sand not to see it, particularly after they have been told again and again and again.”
In Parrilla Bonilla the defendants’ conviction was overturned on appeal because the government failed to prove that the defendants knew they did not belong on the beach. The only sign in that case said “YOU ARE NOW A GUEST ON THIS U.S. MILITARY RESERVATION. ENJOY YOURSELF AND CLEAN UP AFTER YOURSELVES.” Id. at 1380. But the sign that Mrs. McCoy confronted as she walked across the highway toward the island at the entrance to Wurtsmith Air Force Base not only warned her that it was “unlawful to enter this area without permission of the Installation Commander,” it punctuated the warning with a none-too-subtle reference to “military working dog teams.” This was obviously a “Keep Out” sign, not a “Be Our Guest and Enjoy Yourself” sign.
In Parrilla Bonilla “there was no evidence that [the Navy] warned appellants to leave the beach prior to making the arrests.” Id. at 1379. Mrs. McCoy, by contrast, was repeatedly warned to leave the driveway. In Parrilla Bonilla the government failed to show that the defendants had crossed the high tide line, or “brim line,” that the government’s evidence indicated was the de facto boundary of the base. In the case at bar, by contrast, Mrs. McCoy admitted she had stepped over the de facto boundary, and the trial court accepted her testimony.
In their factual aspect, the findings made by Judge Churchill are beyond attack on appeal. Here, as in United States v. Joseph, 781 F.2d 549, 553 (6th Cir.1986), “viewing the evidence in the light most favorable to the prosecution, any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt” (quoting Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 2789, 61 L.Ed.2d 560 (1979)). If the task of this court is to determine “whether or not the district judge’s findings of fact are ‘clearly erroneous,’ ” see United States v. Atwell, 570 F.2d 650, 652 (6th Cir.1978), and United States v. Mowat, 582 F.2d 1194, 1202-03 (9th Cir.), cert. denied, 439 U.S. 967, 99 S.Ct. 458, 58 L.Ed.2d 426 (1978), the task is an easy one; in no way are the findings of fact that Judge Churchill made in this case “clearly erroneous.” After a careful review of the record, we think they were clearly correct.
Ill
The remaining issue that Mrs. McCoy asks us to decide is one that her counsel frames thus:
“Where there was undisputed testimony that the military base commander erased a painted boundary line where previous civilian demonstrations had been conducted, and shifted that boundary line so as to place persons engaged in leafletting into the flow of vehicle traffic along the shoulder of a public highway, was this an unreasonable restriction upon the exercise of First Amendment rights?”
On the record before us, and given the decisions of the United States Supreme Court in Greer v. Spock, 424 U.S. 828, 96 S.Ct. 1211, 47 L.Ed.2d 505 (1976), and United States v. Albertini, 472 U.S. 675, 105 S.Ct. 2897, 86 L.Ed.2d 536 (1985), there is only one possible answer to this question: No.
*833Mrs. McCoy’s brief complains that “[t]he District Court below did not rule upon the reasonableness or unreasonableness of this shifting of the boundary line by the military.” But the undisputed testimony leaves no room for doubt as to the reason why the boundary line that had been painted in after Mrs. McCoy’s first trespass in the driveway was painted out and shifted to the shoulder of the public highway before her second trespass; the line was promptly moved because the military prisoners and master sergeant responsible for painting it misunderstood their instructions and put it in the wrong place. It has never been controverted that the line was shifted in order to put it on what the military authorities had always considered to be the true boundary of the base, and no one asked the district court to “rule” on this obvious fact. There was no need for the district court to address the “reasonableness” of informing the world — including people who, unlike Mrs. McCoy, had not been informed verbally — precisely where the military authorities thought the boundary of the base was located.
From a safety standpoint, it might have been preferable if the line had been left in the wrong place and if the demonstrators had been permitted to stand on the portion of the driveway that lies between the misplaced line and what the authorities considered to be the actual boundary of the base. But “[military bases generally are not public fora,” as the Supreme Court noted in Albertini, 472 U.S. at 686, 105 S.Ct. at 2905; and we reject the notion that the driveway of Wurtsmith Air Force Base had to be turned into a public forum so the county officials would not have to decide whether to let their highway be used for that purpose.
“The notion that federal military reservations, like municipal streets and parks, have traditionally served as a place for free public assembly and communication of thoughts by private citizens,” as Justice Stewart wrote in Greer, is a notion that is “historically and constitutionally false.” 424 U.S. at 838, 96 S.Ct. at 1217. The Constitution of the United States speaks explicitly of the mission of places like Wurtsmith Air Force Base, and that mission is not to provide public forums; it is “to provide for the common defence.” See Greer, id.
There are, to be sure, cases where the military has abandoned its right to control who comes on the streets of its installations. One such case was Flower v. United States, 407 U.S. 197, 92 S.Ct. 1842, 32 L.Ed.2d 653 (1972), which involved a Ft. Sam Houston thorough fare called New Braunfels Avenue. “ ‘New Braunfels Avenue was a completely open street,’ ” and “the military had not only abandoned any right to exclude civilian vehicular and pedestrian traffic from the avenue, but also any right to exclude leafletters.... ” Greer, 424 U.S. at 835, 96 S.Ct. at 1216 (quoting Flower, 407 U.S. at 198, 92 S.Ct. at 1843).
The record of the case before us affords no conceivable basis for supposing that the streets and driveways of Wurtsmith Air Force Base had been “abandoned” to civilian pedestrian traffic and leafletters. Unlike Ft. Sam Houston — and unlike Ft. Dix, the installation involved in Greer — Wurt-smith is a closed base, not an open one. Unlike Ft. Dix, the main entrances of which were not normally guarded and one of which had a sign saying “Visitors Welcome,” Greer, 424 U.S. at 830, 96 S.Ct. at 1214, Wurtsmith Air Force Base has a main entrance that is normally guarded— and the Wurtsmith entrance has a sign which hardly falls in the “Visitors Welcome” category.
Unlike the defendant in Albertini, who entered Hickam Air Force Base during an annual open house, Mrs. McCoy was not standing on the driveway of Wurtsmith Air Force Base pursuant to invitation; she was standing there in open defiance of repeated orders to leave. If, as the Supreme Court held, the streets of the military installations in Greer and Albertini had not been abandoned to leafletters, it is simply not arguable that the main entrance of Wurt-smith Air Force Base had been so abandoned.
*834Had the entrance to Wurtsmith been turned into a public forum, the base commander could still have adopted reasonable regulations to govern the time, place, and manner of distributing leaflets there. But contrary to the assumption on which Mrs. McCoy’s argument rests, the base commander was under no constitutional duty to adopt any time, place, and manner regulations at all — reasonable or unreasonable— for an area that most assuredly is not a public forum and never has been. The mere fact that Mrs. McCoy would have preferred it to be a public forum did not obligate the commanding officer to give up his “historically unquestioned power ... summarily to exclude civilians from the area of his command.” Cafeteria Workers v. McElroy, 367 U.S. 886, 893, 81 S.Ct. 1743, 1748, 6 L.Ed.2d 1230 (1961).
Even if the entrance to Wurtsmith Air Force Base had been a public forum, finally, Mrs. McCoy would still not have been entitled to distribute leaflets there. Unlike the general public, Mrs. McCoy was the recipient of two “bar letters” excluding her from the base under the authority of 18 U.S.C. § 1382. Unlike the defendant in Albertini, who had received his bar letter some nine years before he accepted the commander’s invitation to attend the annual open house at Hickam Air Force Base, Mrs. McCoy had received her most recent bar letter less than two years before she attempted to create her own open house at Wurtsmith. If it was lawful for the Air Force to prevent Mr. Albertini from peacefully passing out leaflets at Hickam during the open house there — and the Supreme Court held that it was — it necessarily follows that the Air Force could lawfully prevent Mrs. McCoy from passing out leaflets within the confines of Wurtsmith Air Force Base.
The convictions are AFFIRMED.
. Section 1382 reads as follows:
“Whoever, within the jurisdiction of the United States, goes upon any military, naval, or Coast Guard reservation, post, fort, arsenal, yard, station, or installation, for any purpose prohibited by law or lawful regulation; or Whoever reenters or is found within any such reservation, post, fort, arsenal, yard, station, or installation, after having been removed therefrom or ordered not to reenter by any officer or person in command or charge thereof—
*827Shall be fined not more than $500 or imprisoned not more than six months, or both.”
(Emphasis supplied.)
. The broken line in the diagram shows where, on May 1, the prisoners painted in the line that was painted out on May 8.
. Nor did Mrs. McCoy’s appellate counsel make a mistake, in our view, by failing to argue that the three misdemeanors with which his client was charged ought to have been tried to a jury. Even contempt of court has been held to be a “petty offense" when the penalty actually imposed does not exceed six months, and “petty contempt like other petty criminal offenses may be tried without a jury....” Taylor v. Hayes, 418 U.S. 488, 495-96, 94 S.Ct. 2697, 2701-02, 41 L.Ed.2d 897 (1974). Cf. United States v. Smyer, 596 F.2d 939, 942 (10th Cir.1979) (“Where the actual sentence for multiple petty offenses is less than six months, there is no jury trial right.”).
The defendants in Smyer could have been imprisoned for up to 990 days, but their actual sentence — imposed after a bench trial for 11 counts of violating the Antiquities Act — came to only 90 days. The defendant in Hayes — convicted on multiple counts of contempt — received sentences which, if served consecutively, would have amounted to several years. Because the sentences in Hayes were to be served concurrently, however, and the penalty actually imposed did not exceed six months in jail, “trial by jury was not required.” 418 U.S. at 496, 94 S.Ct. at 2702. Mrs. McCoy’s actual sentence was less than the actual sentences in Smyer and Hayes, and, just as in those cases, we think it is clear that trial by jury was not required.
. In United States v. Mowat, 582 F.2d 1194, 1206 (9th Cir.), cert. denied, 439 U.S. 967, 99 S.Ct. 458, 58 L.Ed.2d 426 (1976), ”[t]he parties agreed that the Government was required to prove, as an element of the offense, absolute ownership or the exclusive right to the possession of the property upon which the violation occurred." There has been no corresponding agreement in the instant case, and if proceedings under 18 U.S.C. § 1382 are comparable to trespass actions, centuries of legal history support the government’s refusal to concede that anything more than a possessory interest had to be shown.
No less a scholar than James Barr Ames has written that “any possessor may have trespass quare clausum fregit." Ames, Lectures on Legal History, 227. Dean Ames notes that “as early as the twenty-second year of Charles I” the case of *831Johnson v. Barrett, A1.10, established that “an intruder upon the King’s possession might have an action of trespass against a stranger_” Id. Cf. Osway v. Bristow, 10 Mod. 37, from the tenth year of Anne, quoted by Dean Ames as holding that "a possessory right is sufficient to maintain an action of trespass.” Michigan has long since expressed agreement with this centuries-old common law rule. Cf. Gilbert v. Kennedy, 22 Mich. 5, 16-17 (1870) (“Where a trespass consists of a single act, and the plaintiff proves his possession, he may usually rest there”). We see no reason to rewrite the law of trespass at this late date.