Or just contact some of the businesses and offer a classic banner ad on the site.
If done right, it won't even be adblocked (because you can do it with no tracking at all).
Depending on the size of the city, and the queries, you should have a good idea where to look. If not, check the local church bulletins, the local softball/school fields, and anywhere else you find local business advertisements.
Sell it as a 'Google ads back in 2002', frame it in terms of high risk high reward. Sure its unproven, but back in those days, a lucrative click may have only costed $1,$2. When search ads got fully proven, they started costing $100/$200.
If done right, it won't even be adblocked (because you can do it with no tracking at all).
Depending on the size of the city, and the queries, you should have a good idea where to look. If not, check the local church bulletins, the local softball/school fields, and anywhere else you find local business advertisements.