MicroNet Template Big Brothers Big Sisters of York & Adams Counties Share: Nonprofit Organizations Big Brothers Big Sisters of York & Adams Counties Visit Website 227 W Market St., Ste 102 York, PA 17401 (717) 843-0051 (717) 699-0671 (fax) Facebook Twitter About Map About Big Brothers Big Sisters makes meaningful, monitored matches between adult volunteers (“Bigs”) and children (“Littles”), ages 6 through 18, in communities across the country. What's Nearby? Distance: 5 10 15 20 25 50 mi.