Letter Card of Anthracite Coal Mining

I live in the UK, and recently came across a letter card of the Anthracite Coal region at a local auction. There is a link to some images below.
This was published by Scranton News Company.

I thought these pictures may be of interest.

Also, can anyone help me with an approximate date please, and there is no indication on the card?

Here is a link to Goolge Picasa.

http://picasaweb.google.co.uk/vincendj/AnthraciteCoalMining?authkey=Gv1sRgCIW50sra_Oy8_AE&feat=directlink

vincend wrote:I thought these pictures may be of interest.

Also, can anyone help me with an approximate date please, and there is no indication on the card?

Very interesting, thank you. Judging from the pictures I would say they range from about 1890s to almost present day in time. In a one you can see modern equipment and breathing apparatus but most I would guess are in the 1900-1930s range judging from the clothing and miners lamps. I wonder what that sanitairy mule barn smelled like?