They may look like any other orange-vested workers, but a survey crew from Hennepin County has been doing monumental work lately.

It's setting new survey monuments that re-mark key reference points set by the initial government survey of what is now Minneapolis and Hennepin County. That happened in the mid-19th century, and the markers for those points have long since been obliterated by development.

Setting these section corners is one of those little-appreciated tasks that government does. It will mean less research time for surveyors who do future surveys.

Before the government opened up land for sale and settlement, it needed a system to keep track of who owned what. So government surveyors criss-crossed the county with sets of imaginary lines that served as reference points.

Townships that usually measured six miles on each side were created. And sections of land within those townships were checkerboarded with section lines a mile square. Where those lines met, surveyors set posts when wood was handy, or else mounded earth or dug pits to mark these section corners.

Roads often followed these section lines and met at the corners. Road improvements typically obliterated the original corner posts, although subsequent work by private or government surveyors often left records tying the location of these corners to nearby landmarks, if available. In Minneapolis, this led to an accumulation of evidence of where a section corner once was, often in reference to a tree or a power pole or a building corner.

But even those points are fleeting. Trees get old and die. Buildings are torn down and replaced.

The county last marked these section corners in Minneapolis in 1876, but they haven't gotten much attention since, meaning the marks are long gone, often disturbed by road construction. County surveyor William Brown views the current cooperative city-county agreement to re-establish the corners as a last chance before evidence grows too fragmentary. Replacing them with new cast-iron monuments set at ground level involves some detective work.

The county surveyor's office consults records the city used to maintain the center lines of roads that often followed section lines. It can work backward from pipes driven into the ground to mark key points when a subdivision was laid out that used the original corners as a reference point. It consults the notes of surveyors who have tried to establish section corners.

This can sometimes produce conflicting information. Surveyors use different techniques and work in different weather conditions. So Brown's office makes judgments about the reliability of evidence that guided those conflicting measurements. By law, Brown's work becomes the official record when it comes to locating a corner.

The county has reset about 25 monuments so far of a total of 150 section corners and additional markers that quarter those sections. Brown expects to finish the job by mid-2011. Survey corners were reset years ago in the rest of Hennepin County and are field-inspected every five years to make sure they're intact.

The need for these markers is particularly great for redeveloping industrial areas. They serve as reference points that define a redeveloping area such as the new Twins ballpark so that its title can be registered.

So that's what brings a survey crew out to place monuments in locations such as the middle of Lake Street, which straddles section borders. If you're sharp-eyed, you can spot some of its handiwork at the intersection of Lake with Cedar Avenue. A monument was set there to mark one corner where section lines intersected.

Parisi: Dual role OK with city

Two weeks ago, this column raised the issue of whether the city's director of strategic partnerships, Frank Parisi, was caught between conflicting loyalties. That's because he previously served as interim executive director for the nonprofit group advocating a new planetarium, then in his current job developed the city-approved plan to contribute to the planned facility's operating deficit, while serving on its board.

Parisi updated us that his dual role isn't barred by the city's ethics code, as we suspected based on our reading of it. That's based on his consultation with the city's ethics officer, who had previously declined to give us a reading on the matter, saying she was barred from advising people outside City Hall on applying the code. But Parisi said that after further consultation with his boss, City Coordinator Steven Bosacker, he's stepping down from the planetarium board, for appearances' sake.

Steve Brandt • 612-673-4438