According to
remax.com, the Horizon Hills neighborhood is centered around Horizon Drive (as mentioned by
badrunner). I've marked Remax's perimeter on the aerial below.
Google Maps
It's a private road, but until a few years ago you could've seen this sign at the entrance. It looks like there was a fire there at some point since 2015, because
the latest GSV image shows a crude, handmade sign just saying "Horizon".
GSV