I think rikinbbar pretty much corrected your application of the Civil Rights Act. See post #9271456
If the people in question are not public officials they should be able to conduct their buisness occording to the dictates of their concious.
It appears that the city and even the ACLU agree with you, and favor the Hitchin' Post point of view more than I do.....
http://boisestatepublicradio.org/post/coeur-dalene-says-hitching-post-exempt-gay-rights-lawTake note though, that they have had to change the list of their services in order to comply. (read the comments)