Earlier this year, I received an email asking about a relatively recent rock collapse at Grand Portal Point in thePictured Rocks National Lakeshore. Grand Portal Point is a well-known point of rock that juts out into Lake Superior, and it has (or used to have) a small archway underneath through which you could take a canoe, kayak, or similar small craft. In the process of digging up an answer to that email, I acquired some interesting photos and facts to share.

The Great Crash of 1900

Grand Portal Point was within the realm of recent human memory much larger than it is now. It used to contain a massive arch through which you could sail a small ship. That arch collapsed during the night of Sunday, September 16, 1900. The photo in Figure 1 below was taken prior to the collapse, and shows the arch that is gone today. Look carefully toward the bottom left to see a good-sized boat. Look even more carefully at the bottom center to see a canoe in front of the now-collapsed arch.

Figure 1: Grand Portal Point before its collapse in 1900 Photo courtesy of the National Park Service

Figure 1: Grand Portal Point before its collapse in 1900

Photo courtesy of the National Park Service

The photo in Figure 2 was taken sometime shortly after the collapse of the arch. Note the pile of rubble to the right. It's still very conical in shape, indicating that the collapse was recent with respect to when the photo was taken. To the left of the rubble pile you see a large block of rock partially submerged in Lake Superior. I believe this rock to be the pillar that you see labeled in Figure 1. The conical rubble pile, I believe, is largely the remnant of the roof section of the arch.

Figure 2: Grand Portal Point soon after its 1900 collapse Photo courtesy of the National Park Service

Figure 2: Grand Portal Point soon after its 1900 collapse

Photo courtesy of the National Park Service


 

 

 

Munising News Article

 

The following blurb about the 1900 collapse is taken from the "Personal" column of the Saturday, September 22, 1900 issue of the Munising News. (Why it appeared in the "Personal" column, I don't know.) I've preserved the original spelling and grammer.
"The Grand Portal is no more. The roof caved in Sunday night, dropped into the sea, and disappeared from view. The Grand Portal was one of the grandest, most sublime and interesting sights of the Pictured Rocks. The cavity was large enough for a good sized steamer to enter into and it was perhaps a hundred feet or more in hight [sic] from the surface of the water. Frequently large chunks of rock fell from the roof. The portal was formed in this way. The support of the roof was becoming weak, however, and it is presumed that the heavy sea of Sunday night was the cause of the destruction of one of nature's most wonderful and marvelous works. A berry picker who returned from that vicinity yesterday and was encamped within a half mile of the Grand Portal says that when the huge mass of rock fell it shook the ground so that dishes were upset upon the table in his camp. There are other cavities being formed in the rocks in various places and after many yars there will be other grand portals formed by the action of the water, but it may be centuries from now, unless a huge mass of rock should become detached at one time."

The Crash of 1999

I wish I could have been around to see the 1900 collapse, or at least to see first hand what Grand Portal Point was like before and afterwards. All is not lost however. Even today there are opportunities to witness dramatic changes to the Pictured Rocks shoreline. All that's required is to make frequent visits and to have a good memory. Grand Portal Point suffered a second, significant collapse in 1999. Figure 3 is a photo taken before this recent collapse that shows a low archway through which canoers and kayakers liked to travel. You can even see a kayaker entering the arch.

Note: The photos in Figures 3 and 4 were taken from the side of Grand Portal Point opposite to the side you see in Figures 1-2.

 

Figure 3: The low arch, pre-collapse Photo courtesy of Mike Croak

Figure 3: The low arch, pre-collapse

Photo courtesy of Mike Croak

 

The arch shown in Figure 3 collapsed sometime between fall of 1999 and spring of 2000. Figure 4 shows the post-collapse view. The arch is still there, but there's now a rubble pile in the bottom large enough to inhibit kayaker traffic. Essentially, the ceiling dropped out, the floor was built up, and the arch just shifted upwards by a few feet. I've marked a stain that you can see in both Figure 3 and Figure 4. The stain provides a good point of reference so that you can more readily interpret the photos.

Figure 4: The low arch after its 1999 collapse Photo courtesy of Mike Croak

Figure 4: The low arch after its 1999 collapse

Photo courtesy of Mike Croak

 

Chuck Cook, ship Captain for Pictured Rocks Cruises, had the following to say about the collapse shown in Figure 4:

"That was a very dramatic change that we noticed on our first cruise of the 2000 season, the Friday before Memorial Day, 2000. My guess is that it happened sometime earlier in that spring (year 2000), during the freezing/thawing cycles."

Carl Hansen, who runs Northern Waters Adventures, a local kayak outfitter, places the collapse in October or November 1999, with his best guess being October. I have a post-collapse photo that I took on 1-Jul-2000. Mike Croak, who first asked me about this collapse, kayaked underneath the pre-collapse arch on Labor Day 1999. None of these recollections and bits of evidence conflict with each other, and they narrow the possible time of collapse to 6-Sep-1999 (Labor Day) through 26-May-2000 (Friday before Memorial Day). That's as close as I can reliably pin down the time of collapse.

 

Acknowledgments

I would like to thank the following people for their contribution to this article:

  • Gregg Bruff, Park Ranger, Pictured Rocks National Lakeshore, for taking the time to search the park's files to find public-domain photos of the 1900 collapse that I could use in this article.

  • Chuck Cook, Captain, Pictured Rocks Cruises, for responding to my email asking about the time of the more recent collapse.

  • Carl HansenNorthern Waters Adventures, also for answering questions about when the collapse occurred.

  • Mike Croak and Bonnie Peterson for raising the initial question about when the recent collapse occurred.

  • Mike Croak for supplying the photos you see in Figures 3 and 4.