Tirade - Written Language

In some of the parts of Montana and Wyoming, these characters began to appear on some of the sign posts.  I was interested to know what they were, although I did have a suspicion. I stopped at a roadside check where boats were inspected before being allowed further - (see the post on Quagga mussels a year or two ago.)  The young man there on duty confirmed my suspicions that this was Indian writing.  But I said: "I was told that there were no Indian written languages."  He replied that the Blackfeet Indians did in fact have one and this writing was to help keep alive the tradition.  Further research on the Net states that the only indigent people to have a written language in the Americas were the Mayans in Central America.  It seems that a number of Europeans in the 19th century began to write down the sounds of various Indian dialects and this is the script shown above.  Frankly I fail to understand the reason for clinging to a "tradition" that is surely of no use to anyone in the modern world, where a mastery of English is the way for anyone to get ahead with a reasonable job with prospects. Come on People!