I do not think Zion will initially be where people think it will.
I do not think Zion will be at all what people think it will be.
Nor do I think people are at all ready in our current circumstances to begin to learn what Zion will require; what standards of conduct will be required; what covenants will need to be assumed to establish Zion.
I do not think Zion will be an institutional enterprise. The angels will be the ones responsible for that gathering. (See D&C 77: 11, Mark 13: 27.) This presents an apparent impediment to those who either don't believe angels minister to mankind, or who believe they only minister to church leaders, or who think them possible, but have never been administered personally by them.
In the Mark 13 text, the repeated "and then" language of the KJV is not chronological or sequential. It is referring to the generation living at the time it starts, who will live to see it all occur. Meaning "in that day" or more precisely, "among the generation then living."
When there is an abomination that renders desolate in the Temple, you will also see afflictions. You will see those who claim they are Christ, or they are Christ's true living prophet-- though they are not. You will see signs and wonders, including great building projects and the astonishing ability to speak in every language across the world in a single time, but that will not deceive those who take the Holy Spirit for their guide. They will be able to distinguish between the truth and error. Heaven will be shaken. Angels will gather those who follow Christ rather than trust the arm of flesh, and ultimately Christ will return and the world will be wasted at His coming. Though there will be some fragment, like the days of Noah, there will be those who have been gathered by the angels. Those few will be preserved.
Ezra Booth was among the first to hear the original four missionaries sent out at the very beginning of the restoration. He wrote about what Oliver Cowdery told him of the original mission. It was to include identifying the location for the New Jerusalem. Ezra Booth explained: "This is the person commissioned by the Lord to proceed to the western wilds, and as he himself stated, 'to the place where the foot of a white man never trod,' to rear up a pillar for a witness, where the temple of God shall be built, in the glorious New Jerusalem. But alas! he was arrested by man in his course, and by the breath of man the mighty undertaking was blown into the air, and Cowdery was thrown back among the Gentiles, to await for the spirit to devise some new plans in the place of those which had been frustrated. But as the city and temple must be built, and as every avenue leading to the Indians was closed against the Mormonites, it was thought that they should be built among the Gentiles, which is in direct opposition to the original plan." (Ezra Booth, Letter IX, originally published in the Ohio Star in 1831. It has since been reprinted in numerous places and can be found on-line as well.) This is referring to the charge given to Oliver Cowdery, and the other 3 missionaries to find the place where the New Jerusalem would be located. That effort was aborted when the Federal Indian Agents threatened to arrest them if they didn't go back across the line separating the whites and Indians from each other. That line was at Independence, Missouri. So Independence was as close as they could get at the time. By default Independence became the location for the New Jerusalem.
It has remained the location in popular understanding ever since then. Subsequent revelations seem to confirm that as the site.
When Joseph Smith fled Nauvoo on June 22, 1844, and crossed the Mississippi headed west, he explained his purpose was based on revelation. "The Lord warned him to flee to the Rocky Mountains to save his life," according to his brother Hyrum. (DHC Vol. 6, p. 547.) It was there he hoped to locate the Book of Mormon remnant who have the prophetic responsibility to build the New Jerusalem. It will not be built without their involvement.
If the first missionary assignment for this purpose (finding the location for the New Jerusalem to be built before the Lord's return) was directed to the distant west, beyond Missouri, and Joseph's ambition was westward toward the Rocky Mountains, there is reason to suspect that our presumption that the New Jerusalem will be in Independence Missouri is somewhat misplaced. I am persuaded it will not be there until after the Lord's return. There will be a location elsewhere, in the Rocky Mountains, where the preliminary gathering to a Holy City to be built will occur before the Lord's return. Then, following His return, activities will also involve Jackson County.
What precedes His return may be diminutive, but that didn't matter in the case of Noah, so it won't matter in the coming days like the time of Noah. It will be interesting to see how the Lord fulfills His prophecies, promises and warnings, because He does tend to fulfill the prophecies He speaks. Oftentimes not in the way we imagine. Then we will understand the saying "the boundaries of the everlasting hills shall tremble at their presence." (D&C 133: 31.) The initial gathering before the Lord's return will be in the Rocky Mountains.
This gathering will require a kind of social order we are unprepared to live. We cannot be "one" in the sense required for Zion in our present social, political, economic and educational systems. It requires a kind of inter-dependence and cooperation we find repulsive. Even those in the commune on Isaac Morely's farm, after converting to Mormonism, couldn't live the united order and have all things in common. It was this experience, prior to conversion, that led to the revelations about the united order. It fell apart. We've never had a successful long-term experience trying to live withint that kind of system.