Round 1
So I will give you a picture and the stamping and what state it is in for this one.
This one is stamped "5481 10-18-1905 V-A" and is located in California.
So this one is easy if you have experiences with the area. It's located in Yosemite Valley at Clark Point.
From the stamped elevation, you can tell it is somewhere in the mountains. From there, if you are keen you will know that the 1905 dates are common in Yosemite. There were a lot of vertical angle surveys done in Yosemite in 1905, gathering data on the heights of the waterfalls and general elevation data for topography. You won't find these benchmarks on the typical Yosemite quadrangle but they will be on https://pubs.usgs.gov/publication/pp160 on Plate 7. If you also thought it was Yosemite but couldn't find the mark on a typical quadrangle map, then you could search '"5481" yosemite' on Google and it would come up with this link, https://thesurveystation.com/USGS/CA/YosVal_rim.pdf, which leads you to datasheet descriptions of each mark where you could quickly find its location.