I'm don't know much about coal, but here's two points I've picked up:

Anthracite is now a quite small portion of the coal industry, and its primary deposit in eastern Pennsylvania has been mostly depleted.

Mountaintop mining often doesn't glean anywhere near that much - I seem to recall a National Geographic caption about removing a hundred feet of rock for an 18 inche thick seam.

I biased it towards the optimistic for two reasons in particular.  1: Since I probably couldn't come up with exhaustive numbers it's safer that way and would also help "fudge" in some things like underground mines...2:If even the optimistic case turns out pessimistic, you really know it's bad.
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18 inches = 0.4572 meters

1 m^2 of surface area, yields 0.4572 m^3 of coal beneath, or 689 kg of coal beneath for every square meter above.

1 acre = 4,046.85642 m^2

(4046 m^2/1 acre) X (689 kg/m^2) = (2,787,694 kg/acre)

or (6,145,813 lbs/acre) or (3,073 short tons/acre)

1,400 MW consumes 4,818,000 tons per year.

So... 1,568 acres per year assuming a 0.4572 meter thick seam.  Ten times as much - ouch. (That, I imagine, should set the worst case boundry)

Based on this EIA DOE chart, the majority of coal production comes from mines with coalbed thickness around 4-6 feet. But there's a good 42% of production that comes from coalbeds 10 feet thick or greater.

Here's a record of some BLM sales that puts the coal/land ratio in Wyoming around 110 tons/acre. If your 30 tons/acre is true for 58% of the U.S., and 110 acres is true for 42% of the U.S., then the national average might be around 64 tons/acre.  

Correcton: ... BLM sales that puts the coal/land ratio in Wyoming around 110,000 tons/acre. If your 30,000 tons/acre is true for 58% of the U.S., and 110,000 acres is true for 42% of the U.S., then the national average might be around 64,000 tons/acre.  
wow...thanks for digging this up.  I'm surprised at the 110,000 tons/acre figure...no wonder Wyoming pumps out the coal.

Underground - 368,612 (thousand short tons)
Surface     - 762,190 (thousand short tons)

I'm guessing "surface" means strip mining?

Gotta go I'll take a closer look at this later

Sheesh, that was some correction. I'll try again.

... BLM sales that puts the coal/land ratio in Wyoming around 110,000 tons/acre. If your 30,000 tons/acre is true for 58% of the U.S., and 110,000 tons/acre is true for 42% of the U.S., then the national average might be around 64,000 tons/acre.

Note, however, that the Kentucky Geological Survey says that bituminous coal will yield 1,800 tons/acre foot. At a five foot coalbed thickness, that's 9000 tons/acre. Quite a range of estimates! I'm hoping someone with expertise in this field can weigh in.

A can of worms has definitely been opened.  This interests me for sure.  Only time will tell if it can battle my Americanized gnat-like attention span though.  I too hope someone with expertise will weigh in (aka TOD faeries).  But hope can be helped by giving it a chance, so I'll attempt to keep the motivation up, distill what's been learned today and expound a little, and probably drop it into Monday's drumbeat in the hopes of catching a wider audience.  With luck there'll be someone there with some insight.
Electricity - production: 3,892,000,000,000,000 Wh (2003)   https://www.cia.gov/cia/publications/factbook/geos/us.html

Coal is ~50% of the mix.  So 1,946,000,000,000,000 Wh attributed to Coal.

http://www.eia.doe.gov/cneaf/coal/page/acr/table4.html
68% of mines appear to be "surface" mines, so 1,323,280,000,000,000 Wh attributable to surface mined coal.

If a 1,400 MW (continuous duty plant) consumes roughly 13,200 tons of coal per day, which is (33,600 mWh/13,200 tons) or (2.54 mWh/ton).

(1,323,280,000,000,000 Wh) X (tons/2,540,000 Wh) = 520,976,378 tons of coal per year for "surface mined" coal.

Which best case 110,000 tons/acre: (520,976,378tons)X(acre/110,000tons)= 4,736 acres/year

Worst case 3,000 tons/acre (18" seam): (520,976,378tons)X(acre/3,000tons)= 173,659 acres/year

Vermont is 9,250 miles^2 or 5,920,000 acres.

Best case it would take 1,250 years to destroy a Vermont

Worst case it would take 34 years to destroy a Vermont