Kudos and thanks to R.M. for pointing out my mathematical error in the
previous column's calculations.  Turns out the more politically correct answer is approximately 1 archaeological site per every 66 acres of land.

"I made an error in my computations" 
"Oh? This could be an historic
occasion." 
I don't think so.

"Even in this corner of the galaxy, Captain, two plus two equals four." 
Yeah, Yeah, reader, R.M. has already informed us of that.

"Even with intricate machinery as delicately-balanced as ours there is still
a margin for error..."  Well, I'm glad to see that no cruel-hearted Republicans are present in the virtual crowd of individuals viewing this essay.

"I am endeavoring to construct a mnemonic memory circuit using stone knives and bearskins." 

Well, I certainly wouldn't say that I was attempting something that
complicated.

"I do not dispute it. I merely state that it is wrong."
Ok, wrong is wrong and doesn't make a right; anyone else got better data,
assumptions, calculations, theories, concerning the approximate total number of archaeological sites within the continental United States? 

"I need at least two more days before I dare make another attempt."
Remember this is ship time, for actual elapsed time; please conduct psychic seance with Albert Einstein and ask him for a simple answer. 

"I'm sure the Captain would simply have said 'Forget it Bones'."
That sounds good to me, but leave out the 'Bones' reference. 
Too much of a sore subject there for some select individuals.

"I'm sure there is an answer it simply has not yet been discovered."
Boy, isn't that enlightening.  But does that really get us anywhere closer
to the answer?

"Spock, what are the odds of getting a royal fizzbin?"
"I've never calculated them."
Then, perhaps we'll just have to get you to work on these computations for us.

Anyway, below are the corrected figures. 
Would invite any and all for comments, criticisms, expounding ideals, etc.  Especially interested in approximate number of artifacts found at  an average archaeological sites.  I'm curious as to the number of artifacts lost due to the  development of 1,200,000 acres of land (in the past 3 years) here in the great State of Texas.
 

Area: 
total: 9,629,091 sq. km 

1 square mile = 640 acres = 2.590 square kilometers 

Per BLM article above:4 million sites \ 264 million acres  = approximately 1
archaeological 
site for every 66 acres

9,158,960 sq. km \ 2.590 sq. km = 3,536,278 square miles total land area of
U.S.A. 
3,536,278 square miles * 640 acres in one square mile = 2,263,217,920 total
acres 

2,263,217,920 total acres \ 66 acres per site = approximately 34,291,180
total archaeological sites scattered throughout the continental United States of America.