My first attempt took my wife and me on Route 42 from South Dakota into Iowa, and we ended up in Larchwood, where I got the names of some roads and headed back north, first finding the Tri-state point, where Iowa, Minnesota and South Dakota meet. It's not at the northwest corner but east of it, with part of South Dakota sitting on Iowa's northern boundary.

       Then we headed west along the road that follows the state line, till we came to where the road turned north (268th St. at 481st Ave.). At that point, the physical corner of Iowa was still somewhere out ahead in the distance, where the Big Sioux River formed the state's western boundary. 

        At this turning point in the road, there's a state preserve on the Iowa side. I ventured inside the preserve and followed a path, looking for the corner.  I had gone a ways and wasn't soon finding it.  It seems I noticed I was walking away from the state line so I turned back to my entry point, where my wife was waiting, and worrying. I gave up the quest for that day. I would come to learn this preserve was called Gitchi Manitou.

        From a map, I saw that 57th Street in Sioux Falls seemed to be about the same latitude as the Iowa border, so the day we left to go back to Illinois, I decided to detour, to look for the corner from the Dakota side. I followed 57th Street east and ended up on a farm lane. I was told the river was about a mile and a half away.  Nearby was a gated road.  We drove around looking for a way to get to the river.  Coming back toward that farm, we stopped at a house to inquire and the lady there said they had the key to the gated road, leading toward the river.   It happened that the gate was shut but not locked.  We got permission to go on that road which takes you eastward and down a hill where there's a pump station for Sioux Falls. To the right of it was a hayfield with big rolls of hay. We walked that way and I eventually came to the river whose water was running high. I walked along its bank for a ways and shot a few pictures, including a couple downstream.   I could've then been about in line with 57th Street.  We walked back to the car and resumed our trip back to Illinois, still not knowing exactly where the corner was across the flow. 

        It happened that we had occasion to return to Sioux Falls this autumn, to help a daughter-in-law, having surgery. While there, I took some time to try for a third time to seek out the corner. I drove to the road that takes you to the corner by Gitchi Manitou.  Coming near it, I drove down a long farm lane and asked permission to walk on their land. The farm is owned by Carol Archer whose son Rick was there painting her house. He suggested I go to the corner where I'd been before, and follow the fenceline of the farm pasture. He also said that, were he not trying to finish painting before rainy weather arrived, he would've accompanied me. 

        I managed to get through the barbed wire and walk along the fence on the state line. Here and there were outcroppings of rock. In one place, rock from Iowa seemed to bulge through the fence into South Dakota (the fence was built around it).  I came to a couple pieces of low fence blocking my path, stepped over them and found my way through some trees in a wooded area.  Eventually I came to a spot where the border fence ended and a sign indicated the boundary of the preserve turned, with a L- shaped arrow. The Big Sioux was still a short distance away. I went down a dip, came to the riverbank, and walked to my left .

        As far as land is concerned,  I was at the northwest corner of Iowa.   I saw tall grass and fallen timber but no marker for the geographical location.  By the river ahead of me, was a group of large trees, maybe cottonwood.  The Big Sioux was flowing by, with some rocks scattered in the water.   I would later learn there was a wagon crossing at this spot in the river.  The river is named for the Sioux nation who lived in the area, and the Big in Big Sioux is said to refer to its size or to differentiate it from another Sioux river, the Little Sioux over in Iowa.  At one time the Big Sioux  even had the Indian name for Calumet River, a calumet being a long-stemmed peace pipe  (Upstream it flows within about 13 miles of Pipestone, Minnesota.  A Lewis and Clark map of 1814 shows the river as the Sioux, with a tributary called Red Pipestone R.).

        From where my car was parked outside the pasture, I estimated it was about 3/8 of a mile to the river. Back from my walk to the corner and through the barbed wire once more, I walked over into the Gitchi Manitou Preserve to see if I could find a rock formation I'd seen when I'd been inside that area months earlier. Taking a side path, I found a rock quarry enclosing water, with scenic views. My approach was crowned with a picturesque mass of rocks.   I can imagine Indians standing on that very formation talking about what they saw before them, and gesturing as they did so.