The great circle through both monuments would intersect the middle of
the lake north of both monuments, perhaps reconciling the USGS given
position with your average, Mike. My spherical trigonometry is too
rusty to yield a quick answer. Anybody else?

By the way, I'm rooting for some beer to go with all that ice.

BJB

> such an averaging will produce a tripoint position of
> nad27 45d00m38s3775 x 73d20m40s036
> which tho probably unreliable beyond tenths of a second
> still seems far more credible than the usgs positioning
> which incidentally has the additional defect
> of placing the tripoint north of both monuments
> yikes
> for how could that be true
>
> while neither position is terribly punctilious
> they both still afford target areas of about 10 foot circles
> whose centers are more than 100 feet apart