There are tons of great rivalries throughout the small schools in western PA that dont get mentioned much because overall they arent always successful teams and they are so small that their game doesnt move more than the local needle. The consolidation of schools in Beaver County to make central valley took away lots of great ones, Blackhawk, Beaver, Beaver Falls, New Brighton, Western Beaver, SSB, etc against each other were always great games.
Washington and Greene Counties have quite a few schools with less than 300 total kids So you have 20-25 man rosters and the whole town shuts down on Friday home or away. West Greene, Carmichaels, Mapletown, Jeff-Morgan, Monessen, Charleroi, Ringgold, Wash high, Char Houston, Avella, Burgettstown, Fort Cherry all have 'packed houses' each Friday night, its just that it's under a 1000 people because the two teams dont have that many people total.