PAD protected area only have state name attribute, but don't have county name attribute.
How to look up PAD layer by county line?
You can mix county line layer from somewhere, anywhere, with PAD layer by viewer model number '2004'.
Viewer model '2004' allow you mix 2 to 6 layers from anywhere, somewhere.
https://transparentgov.net:3200/googlemaps2004/default?layer_id=12&layer=Counties¢er_lat=36.14276207878793¢er_long=-115.01003699920267¢er_zoom=7&url=https%3A%2F%2Fgisportal.hrsa.gov%2Fserver%2Frest%2Fservices%2FAnalyzerTool%2FAnalyzerTool%2FMapServer&org=https%3A%2F%2Fgisportal.hrsa.gov%2Fserver%2Frest%2Fservices&panto=0&overlayType=overlayType_image&select_field=10&select_fieldvalue=5&distinctorgroupby=distinct&orderbycountorvalue=orderby_value&url2=https%3A%2F%2Fgis.usgs.gov%2Fpadus%2Frest%2Fservices%2Fpadus3%2FManager_Type%2FMapServer&layer_id2=0
How to do it
1) find the county line layer at HRSA server, click '2004'
https://transparentgov.net/json2tree/esri/server/folder.html?org=https%3A%2F%2Fgisportal.hrsa.gov%2Fserver%2Frest%2Fservices&url=https%3A%2F%2Fgisportal.hrsa.gov%2Fserver%2Frest%2Fservices&select_folder=118&select_layer=12
2) find PAD protected area layer, copy this layers arcgis rest api endpoint, will paste it later in 2004
https://transparentgov.net/json2tree/esri/server/folder.html?url=https%3A%2F%2Fgis.usgs.gov%2Fpadus%2Frest%2Fservices&org=USGS+Protected+Areas+PAD%2C%26nbsp%3B%26nbsp%3B&cross=default&timeout=10000&select_folder=11&select_layer=0
3) click setting > paste PAD rest api endpoint in here
https://transparentgov.net:3200/googlemaps2004/default?layer_id=12&layer=Counties¢er_lat=43.46085923043201¢er_long=-116.24415999149997¢er_zoom=10&url=https%3A%2F%2Fgisportal.hrsa.gov%2Fserver%2Frest%2Fservices%2FAnalyzerTool%2FAnalyzerTool%2FMapServer&org=https%3A%2F%2Fgisportal.hrsa.gov%2Fserver%2Frest%2Fservices&panto=0&overlayType=overlayType_image&select_field=4&select_fieldvalue=3&distinctorgroupby=distinct&orderbycountorvalue=orderby_value&url2=https%3A%2F%2Fgis.usgs.gov%2Fpadus%2Frest%2Fservices%2Fpadus3%2FManager_Type%2FMapServer&layer_id2=0
4) Done you just mixed 2 layers from 2 different federal department