These T-wall structures in Rosemount are part of the historic Gopher Ordnance Works site. It is now time for this site to be developed into a new state park. (Provided by Dan Maruska/The Minnesota Star Tribune)

As you drive along a county highway in the southeast part of the metro area, on the stark dividing line where new subdivisions meet old farm fields, you begin to pass several enormous concrete structures.

Row after row they continue, these massive T-walls that don't appear to serve any recognizable purpose.

These structures are part of the historic Gopher Ordnance Works site. It is now time for this site to be developed into a new state park.

The T-wall structures stretch for a half mile along the south side of 160th Street in Rosemount, southeast of the intersection of 160th Street (County Road 46) and Akron Avenue. You can see them on any map app or website with a satellite view.

But the T-walls occupy only a small, 40-acre parcel of the site that should be developed into a park, in addition to the 200 acres of ruins of three artillery production lines and smokestacks to the north of 160th Street (which did not exist when they were active), and a second set of 49 more T-walls one block to the east, on 45 acres south of 156th Street between Barbara and Blaine Avenues.

Combined, the ruins cover only 285 acres of the University of Minnesota's 5,000-acre UMore Park, which itself was carved out of the full former Gopher Ordnance Works site.

That original site was a sprawling, 11,500-acre, 858-building facility that manufactured gunpowder during World War II, and which was transferred to the U when the war ended.

The T-walls were parts of structures called "solvent recovery houses," where small rail cars containing gunpowder parked to have flammable ethanol and diethyl ether removed for reuse on the three production lines — where limited but precious remains still stand south of 155th Street between Akron and Angus Avenues.

The three production lines have largely been demolished over the years, but the ruins that remain still tell the dramatic story of this place — its historic significance, the court battles involving the displacement of Dakota County farmers, and the lives of the 20,000 construction workers who built the place and the people who worked there.

This northern parcel could simply be cleared of brush and the numerous tripping hazards a U team cataloged in 2015, after which several walking paths could be laid to wind through the area, lights and benches installed, and certain ruins restored and made safe or at least approachable. A spacious parking lot could easily be constructed in the now empty field north of 160th Street.

The T-walls are the main attraction. This space would attract everyone from casual picture-takers and influencers in search of a new location, to artists from all of Minnesota's arts traditions.

Photographers would capture the concrete in black and white, painters would portray the different colors that appear during different times and seasons, artists who draw in charcoal would depict shadows and shades, filmmakers and musicians shooting videos would appreciate the drama of this alien landscape, and users of emerging technologies like drones and cellphone LIDAR sensors would make exciting new visuals.

This is one of the most historically significant World War II sites in Minnesota, a lesser-known sibling to the Twin Cities Army Ammunition Plant in Arden Hills. However, TCAAP is a federally designated Superfund site, while the Gopher Ordnance Works site is not. Several assessments, including the Minnesota Pollution Control Agency's 1981 investigation and the U's 2017 remedial investigation, concluded that the site can be made safe with targeted cleanups.

It's important now to preserve the T-walls and what remains of Gopher Ordnance Works because several former structures on this site have been demolished as recently as 2016, including five towering smokestacks and an enormous spherical reservoir. Additionally, the U's 2008 master plan for the area envisions "13,000 houses plus multi-family dwellings accommodating 20,000 to 30,000 residents," and an "office and wellness complex incorporating professional offices and health and wellness facilities."

This is a wonderful piece of Minnesota's history that needs to be preserved, just like treasures such as the Stone Arch Bridge, Mill Ruins Park and Duluth's Canal Park. To let it sit unused would continue to be a waste, and to destroy it would be unforgivable.

Dan Maruska lives in St. Paul.