Appellants John Ecclestone II, Luella Bassett, Kim Leith, Helen LaValley, Jacqueline Hudson, Peter Dougherty, and Elizabeth LaForest appeal from a judgment entered December 11, 1990, after a bench trial, in the Eastern District of Michigan, Robert H. Cleland, District Judge, upon a *1311verdict of guilty on the charge of wrongfully entering a military base in violation of 18 U.S.C. § 1382 (1988).
On January 17, 1991, Judge Cleland sentenced Ecclestone to 12 months probation and a $2,000 fine; Bassett to 60 days imprisonment and a $1,000 fine; LaForest to 21 days imprisonment and a $1,000 fine; Leith to 12 months probation and a $2,000 fine; LaValley to 12 months probation and a $2,000 fine; Hudson to 60 days imprisonment and a $1,000 fine; and Dougherty to 60 days imprisonment and a $1,000 fine.
Appellants have appealed their convictions. Execution of their sentences has been stayed pending appeal.
Appellants assert several claims of error, including, among others, the following: (1) LaValley, Hudson and Ecclestone contend that they were improperly denied a jury trial; (2) Dougherty contends that he was barred improperly from entering the base; (3) Ecclestone, Bassett, LaForest and Leith contend that they did not reenter the base as alleged by the government; (4) Eccle-stone, Bassett, LaForest, and Leith contend that the district court erred in allowing the government to introduce certain evidence in violation of the hearsay rule; and (5) Dougherty contends that his first amendment rights were violated by the military’s “selectively targeting political or protest demonstrations” in an area open to the public.
Furthermore, Ecclestone, Bassett, La-Forest and Leith contend that they were denied fundamental fairness and due process because they were told by the military that $500 was the maximum fine and the actual fines imposed exceeded that amount.
Moreover, Dougherty contends that, since he received a bar letter in 1983 and was convicted in 1987 of unlawful re-entry onto Wurtsmith Air Force Base (WAFB), the double jeopardy clause bars his prosecution; and that his Fourth, Fifth and Sixth Amendment rights were violated when he was detained for four hours, fingerprinted, and questioned regarding his date of birth, driver’s license and address.
For the reasons that follow, we affirm the convictions of all appellants.
I.
We shall summarize only those facts and prior proceedings believed necessary to an understanding of the issues raised on appeal.
WAFB is a federal military installation located in Iosco County, Michigan. The federal government has granted Iosco County a one hundred fifty foot easement for the construction, maintenance and use of county highway F-41 which runs adjacent to WAFB. In addition to covering the roadway, the easement extends to cover approximately sixty feet on each side of F-41. On the base side of the highway, the easement includes a grass strip located between the “white line” marking the edge of the roadway, and a permanent chain link fence. Appellants assert that this strip is used frequently by pedestrians, joggers, and snowmobilers in the winter months.
On August 4, 1990, an orange snow fence, approximately three to four feet high, was placed along the white line marking the entrance to the base. The fence extended along the white line adjacent to F-41 for some distance until it ended running perpendicular to the road, across the grassy strip, and joining the permanent steel chain link fence. Pedestrian traffic was blocked on the grassy strip adjacent to WAFB at the point where the snow fence intersected the permanent steel fence. Senior Master Sergeant Brian Clever testified that appellants, along with a group of approximately four hundred other protestors, marched down the grassy strip toward the base entrance until they encountered the orange snow fence. Warning signs were mounted on the snow fence roughly every twenty feet, stating: “It is unlawful to enter this area without permission of the installation commander.” On August 4, 1990, protestors pushed down the snow fence and about one third of them entered the restricted portion of WAFB. At this time, Sergeant Clever read the following prepared statement to appellants, ordering them to leave the base:
“You are on a United States military reservation at Wurtsmith Air Force Base, Michigan. *1312Specific permission of the installation commander is required for entry onto Wurtsmith Air Force Base and that permission has not been granted.
The installation commander has determined that any political or protest demonstration taking place within the boundaries of Wurtsmith Air Force Base could interfere with the mission of the 379th Bombardment Wing.
By order of the installation commander, Wurtsmith Air Force Base, you are hereby ordered to leave Wurtsmith Air Force Base.
Your continued presence in Wurtsmith Air Force Base will place you in violation of the lawful order to leave and you will also be in violation of lawful regulations prohibiting your entry onto Wurtsmith Air Force Base.
Your continued presence on Wurtsmith Air Force Base may render you criminally liable for violation of federal law. You are again ordered to depart Wurt-smith Air Force Base immediately.”
Since appellants failed to leave after receiving these warnings, they were detained for wrongful entry onto a military base in violation of § 1382. Air Force personnel recorded these events on video tape and presented the tapes as evidence at appellants’ trial.
The district court found that appellants previously had entered WAFB and had received letters from the base commander barring them from future entry. These findings were based on testimony by Sergeant William Stern, a noncommissioned officer in charge of the Security Police Reports and Analysis Section, that letters barring from the base all appellants were prepared and maintained in the ordinary course of business. The court found that these letters established that appellants previously had wrongfully entered the base and had been barred from future entry by the base commander. These documents were admitted pursuant to the business records exception to the hearsay rule. Fed.R.Evid. 803(6).
In rendering his decision, Judge Cleland made two additional pertinent findings. He found that “the area in question in this case had not been converted into any form of a public forum for the dissertation of political or religious or any other kind of protected speech”, and that the First Amendment is not “implicated in any way in this case.”
II.
We turn first to the contentions of LaValley, Hudson and Ecclestone that they were entitled to a trial by jury because a violation of § 1382 is a “serious” rather than “petty” offense. The Sixth Amendment provides that “[i]n all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed_” U.S. Const, amend. VI. The Supreme Court, however, has not pursued a literal interpretation of this language, carving out an exception to the rule for “petty offenses”. E.g., Blanton v. North Las Vegas, 489 U.S. 538, 541 (1989). A “petty offense” is one in which the defendant would be subject to no more than a six month period of incarceration. Id. at 542-53 In cases where the maximum sentence cannot exceed six months, “[a] defendant is entitled to a jury trial in such circumstances only if he can demonstrate that any additional statutory penalties, viewed in conjunction with the maximum authorized period of incarceration, are so severe that they clearly reflect a legislative determination that the offense in question is a ‘serious’ one.” Id. at 543 (emphasis added). Such situations, however, are rare. Id. Since the maximum statutory punishment for violations of § 1382 is only a six month period of incarceration, a fine of $5,000 and a five year term of supervised release, the offense is “petty” within the meaning of Blanton. Appellants accordingly are not entitled to trial by jury. United States v. Floyd, 477 F.2d 217, 222 (10th Cir.), cert. denied, 414 U.S. 1044 (1973) (“The violation of [sjection 1382 ... constitutes a petty offense not requiring a trial by jury.”).
Ecclestone asserts an additional challenge to the district court’s denial of a *1313jury trial. Ecclestone is licensed to practice law in the State of Michigan. His license may be revoked by the Michigan Supreme Court for violations of the laws of the United States. Cf. United States v. Craner, 652 F.2d 23, 26 (9th Cir.1981) (“the threat of loss of a license as important as a driver’s license ... is another sign that the DUI defendant’s community does not view DUI as a petty offense”). We reject Eccle-stone’s contention that this additional factor made his violation of § 1382 a “serious” offense. His contention is without merit because the revocation of his bar license is not statutory and because the revocation of his license would not directly follow a conviction under § 1382. Michigan Court Rules § 9.110-12 (providing for a full hearing before a review board prior to the revocation of an attorney’s license). Moreover, Ecclestone’s assertion, pursued to its logical conclusion, would mean that lawyers have a special right to jury trials because their licenses arguably may be revoked for any infraction of the law. We decline the invitation to create such an exception to Blanton.
III.
This brings us to the merits of appellants’ contentions that their conduct was not prohibited by § 1382. Ecclestone, Bas-sett, LaForest, Leith and Dougherty contend that the prosecution of them was wrongful because the evidence is insufficient to support a conviction under § 1382 which provides in relevant part:
“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 ... [s]hall be fined not more than $500 or imprisoned not more than six months, or both.”
The Alternative Fine Act, 18 U.S.C. § 3571 (1988), raises the ceiling on the maximum fine for infractions of § 1382 from $500 to $5,000. Appellants contend that two of the prerequisites of § 1382 have not been satisfied. Ecclestone, Bassett, LaForest and Leith argued that they did not wrongfully re-enter the base. Dougherty, on the other hand, contends that he was not barred previously from WAFB by the base commander.
(A)
We first turn to the contention of Ecclestone, Bassett, LaForest and Leith that there was insufficient evidence to support their convictions because the federal government had granted Michigan an easement to use the land adjacent to highway F-41, and appellants therefore were lawfully on the grassy strip at the time they were taken into custody. We disagree.
In United States v. McCoy, 866 F.2d 826 (6th Cir.1989), we held that the grassy strip in question is part of WAFB. In McCoy, we addressed the issue as to whether the driveway at the main entrance to WAFB is part of the base for purposes of § 1382. In resolving that issue, we cited the district court’s finding that “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_” Id. at 831. The grassy strip on which the protéstors were apprehended in the instant case was within the boundary that we already have determined to be part of the base. The mere fact that an easement had been granted to the state for the construction, maintenance and use of highway F-41 did not give the protestors the right, in bold defiance of military authority, to enter the base, after being previously barred.
A different question would be presented if appellants’ only intrusion into the base was driving an automobile on F-41. Id. In United States v. Albertini, 472 U.S. 675 (1985) (Stevens, J., dissenting), a case where a defendant was convicted under § 1382 for re-entering Hickam Air Force Base, Hawaii, Justice Stevens stated that “highways or other public easements often bisect military reservations,” and that:
“If an individual who has been removed from Hickam is liable under § 1382 whenever he is thereafter ‘found within’ its boundaries, he risks criminal punishment every time he departs on an airline flight that may use the runway travers*1314ing the base. The use of these military lands for the limited public purposes for which they have been set aside does not involve the bold defiance of authority that is foreseen by the structure of the statute and reflected in its legislative history.”
Id. at 698-99
Unlike Justice Stevens’ hypothetical person innocently traversing a highway or crossing a military runway, appellants in the instant case boldly defied military orders. They crossed over a snow fence on which warning signs were posted. They remained on the base even after they were ordered to leave by the base authorities.
For these reasons we hold that the district court’s conclusion that appellants had re-entered WAFB unlawfully was not erroneous.
(B)
We turn next to Dougherty’s contention that there was insufficient evidence to support his conviction because the bar orders were improperly issued. Specifically, Dougherty contends that the orders were invalid because they were not prepared by the base commander and he had not been barred previously from the base within the meaning of § 1382. In making this contention, Dougherty points to the “fill-in-the-blanks” nature of the bar letters. We are not persuaded.
The district court held that, although the bar letters were pre-signed by the base commander, they were issued only after the commander had given his authorization on a case-by-case basis. Contrary to Dougherty's contention, there is no requirement that the base commander perform the administrative task of “filling-in-the-blanks” in the bar letters. There is no basis for concluding that the district court’s holding that the bar letters were properly issued was erroneous.
IV.
We now turn to the contention of Ecclestone, Bassett, LaForest, and Leith that the district court improperly admitted the bar letters pursuant to the business records exception to the hearsay rule because the letters were prepared for the purpose of litigation. We find no merit in this contention.
The district court stated: “The testimony, the Court is satisfied, does establish that the records were kept in a regular fashion, that they were part of a regular activity of the enterprise and the provisions of 803(6), I think are sufficient.” Although “conclusions of law, such as whether proffered evidence constitutes hearsay within the meaning of Federal Rules of Evidence, are reviewed de novo,” United States v. Levy, 904 F.2d 1026, 1029 (6th Cir.1990), cert. denied, 111 S.Ct. 974 (1991), the issues to be resolved in the instant case do not involve either questions of law or the application of the law to factual determinations. Rather, the district court simply made factual findings that the bar letters were not prepared for purposes of litigation. Since we will not set aside a district court’s findings of fact unless clearly erroneous, Whitney v. Brown, 882 F.2d 1068, 1071 (6th Cir.1989), and since we hold that the court's factual findings were not erroneous, we reject appellants’ contention that the bar letters were improperly admitted.
V.
Finally, we consider the contention of appellant Dougherty that his First Amendment rights were violated by the government’s “selectively targeting political or protest demonstrations” in an area open to the public. This argument is without merit. Military bases are not public forums. Greer v. Spock, 424 U.S. 828, 838 (1975) (“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 is thus historically and constitutionally false.”); McCoy, supra, 866 F.2d at 832-34. Because we have already held that the grassy strip where appellants were apprehended was part of WAFB, Dougherty’s claim must necessarily fail. Furthermore, even if the area in question is a public forum, *1315appellant’s claim still fails. In Albertini, supra, 472 U.S. at 688 the Court found that § 1382 is content-neutral, and “[t]he First Amendment does not bar application of a neutral regulation that incidentally burdens speech merely because a party contends that allowing an exception in the particular case will not threaten important government interests.” We find that appellant’s speech was at most only incidentally burdened. The bar letters only forbid his entrance onto the WAFB, appellant was still free to protest outside of the base.
VI.
To summarize:
We hold that appellants’ convictions should be affirmed. First, since we hold that a violation of § 1382 is not a “serious” offense for Sixth Amendment purposes, the district court did not err in denying appellants a jury trial. Second, there is no basis for concluding that there was insufficient evidence to support appellants’ convictions. Despite the lawful issuance of letters barring appellants from WAFB, appellants boldly defied military authorities. Third, there is no support for appellants’ claim that the district court was clearly erroneous in admitting the bar letters pursuant to the business records exception to the hearsay rule. Finally, the military’s prohibition on appellants entering WAFB did not violate the First Amendment. We find no merit in any of appellants’ claims of error.
Affirmed.