Question: Which professor said it was impossible to impanel a jury in alignment with the Vicinage Clause?
About the article "Yellowstone National Park", section "Legal jurisdiction".

Candidate passages:
The entire park is within the jurisdiction of the United States District Court for the District of Wyoming, making it the only federal court district that includes portions of more than one state (Idaho, Montana, and Wyoming).
Law professor Brian C. Kalt has argued that it may be impossible to impanel a jury in compliance with the Vicinage Clause of the Sixth Amendment for a crime committed solely in the unpopulated Idaho portion of the park (and that it would be difficult to do so for a crime committed solely in the lightly populated Montana portion).
One defendant accused of a wildlife-related crime in the Montana portion of the park attempted to raise this argument.
He eventually pleaded guilty.
The United States District Court for the District of Wyoming (in case citations, D.
Wyo.)
is the Federal district court whose jurisdiction comprises the state of Wyoming and those portions of Yellowstone National Park situated in Montana and Idaho.
The court has locations in Cheyenne and Casper.
Appeals from this court are heard by the United States Court of Appeals for the Tenth Circuit (except for patent claims and claims against the U.S. government under the Tucker Act, which are appealed to the Federal Circuit).
The United States Attorney's Office for the District of Wyoming represents the United States in civil and criminal litigation in the court.
The district of Wyoming is the only federal court district that includes portions of more than one state.
Law professor Brian C. Kalt has argued that it may be impossible to impanel a jury in compliance with the Vicinage Clause of the Sixth Amendment for a crime committed solely in the Idaho portion of the park (and that it would be difficult to do so for a crime committed solely in the Montana portion).  
Before the adoption of the federal Constitution, only two state constitutions provided an explicit vicinage right.
The Virginia Constitution of 1776 provided: "in all capital or criminal prosecutions a man hath a right to .
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an impartial jury of twelve men of his vicinage."
The Pennsylvania Constitution of 1776 read similarly, but said "county" instead of "vicinage"; it was amended in 1790 to say "vicinage.
"By contrast, four of the original thirteen state constitutions contained explicit criminal venue provisions.
New Hampshire (1784) and Georgia (1777 and 1789) required crimes to be tried in the county where committed.
Maryland (1776) and Massachusetts (1780) contained similar provisions.
In "Coleman's Appeal" (1874), the Supreme Court of Pennsylvania held that "a man shall only be liable to be called on to answer for civil wrongs in the forum of his home, and the tribunal of his vicinage."
The New Jersey Plan contained a provision that: "o person shall be liable to be tried for any criminal offense, committed within any of the United States, in any other state than that wherein the offense shall be committed .
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The proposals of Alexander Hamilton and Charles Cotesworth Pinckney were similar.
The Committee of Detail and Committee of the Whole amended this language and included it within Article Three, Section Two, Clause Three.
Article III provides: "The Trial of all Crimes .
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shall be held in the State where the said Crimes shall have been committed."
This provision received almost no debate in the Constitutional Convention.
The omission of a vicinage right from the United States Constitution was among the objections of the Anti-federalists to the ratification of the Constitution.
James Madison explained the omission of a vicinage clause in the Virginia Ratifying Convention as follows: It was objected yesterday, that there was no provision for a jury from the vicinage.
If it could have been done with safety, it would not have been opposed.
It might so happen that a trial would be impracticable in the county.
Suppose a rebellion in a whole district, would it not be impossible to get a jury?
The trial by jury is held as sacred in England as in America.
There are deviations of it in England: yet greater deviations have happened here since we established our independence, than have taken place there for a long time, though it be left to the legislative discretion.
It is a misfortune in any case that this trial should be departed from, yet in some cases it is necessary.
It must be therefore left to the discretion of the legislature to modify it according to circumstances.
This is a complete and satisfactory answer.
Virginia ratified the Constitution, with a proviso that a Bill of Rights, including a right to "trial by an impartial jury of his vicinage," be added by amendment.
North Carolina adopted the same proviso as Virginia, but refused to ratify the Constitution in its absence.
New York and Rhode Island ratified the constitution with similar provisos as Virginia (but, in the case of Rhode Island, the Sixth Amendment had already been sent to the states for ratification).
The ratifying provisos of Massachusetts did not include a vicinage right; a proviso including a vicinage right was considered and rejected in Pennsylvania. 
 "Jury..." Interpretation.
The Vicinage Clause applies only to petit juries, not grand juries (although some cases finding no violation of the Clause have assumed without deciding that the Clause does apply to grand juries).
"...of the State and district..." In murder cases arising from the Indian Territory, Navassa Island, and the No Man's Land of the Oklahoma Panhandle, the Supreme Court has held that the Clause places no limits on the prosecution of crimes committed outside the territory of a state.
The Clause does not require a jury drawn from the judicial division (a subset of a federal judicial district) within which the crime occurred; rather, the jury may be drawn from any division of the district.
Nor does the Clause prevent the jury from being drawn solely from a judicial division, or any other subset of a judicial district (rather than the entire judicial district).
"...wherein the crime shall have been committed..." The "wherein the crime shall have been committed" language of the clause is in parallel with the venue provision of Article Three—"where the said Crimes shall have been committed.
"—and with Rule 18 of the Federal Rules of Criminal Procedure—"where the offense was committed."
The three provisions have been interpreted in tandem to refer to the locus delicti of the offense.
"...which district shall have been previously ascertained by law" Lower courts are split on whether the Clause requires that the defendant be tried in a judicial district that was in existence at the time the crime was committed.
Some courts have held that it does.
Others have held that it does not and that the district need only be ascertained prior to trial.
Even proponents of the former view have found no infirmity when Congress prospectively divides a judicial district, but retains the former configuration for past offenses.