Hi,
Yes, there is a block association for the 300 block of west 15th Street. We plant flowers around the trees the first saturday of May each year, and have an occasional meeting when people want one. (Unlike the 200 block, which has monthly meetings; that sounds like too much work!) I also represent the block at various hearings and meetings in the city.
I also post information about the neighborhood on a page in my own website:
www.jamesmjasper.org.
I'm sorry it took me so long to find this site, but I'll put a link from my own website.
Yours,
Jim Jasper