I agree with Tall Trees that this boulder is unique. Whether is was an Indian grinding stone or the holes were caused by water remains the question. Oddly, we have a very similar rock here with pretty much identical holes.. but it is small.. like a foot in length. Mom found it somewhere and we always assumed the holes were caused by water erosion.
Back to that beer can for a minute. In the interest of history I took the time to look up both when 'pull tabs' were introduced and the Bud can labels over the years. Seems like pull tabs were first introduced in 62/64. So, it may be teetering on the 50 years. And, I could find no Bud can that was blue. So, perhaps another product of the same company. I dunno. But, I will find this. You know.. in the interest of history and the fact that I want that can. cheryl o7o