I've run across two major infestations in Salt Lake county of spam.
The first is State Street/Factory Outlet Drive between 106th South and 123rd South. Almost all of it is on the northbound side, some are attached to real estate signs, others are attached to other things, along with some stand-alone stuff. Most is yellow in color. Didn't see the contents due to being on a bus.
The other one was at 62nd South and 56th West. This is by a Wal-Mart, mostly real estate agent seeking apprentice and we buy housese type stuff. Check around any Wal-Mart as this could be prime territory for spammers. Large shopping districts such as Jordan Landing, etc., may be easy pickings as well.
Found a spam on the ramp from northbound I-15 to Bangerter Highway. There's a parking lot by the barrier for the ramp, the spam is mounted apparently just as the ramp starts to go up. You'll have to walk through the parking lot to get to it. Take Bangerter to the east of I-15, then turn on 138th South, that is an east-west road that becomes the frontage road just past the lot you'll have to go through to get this one yanked.