Layer Estimates:

Layer: USA_CountyGeoJSON_polygons (ID:1)
Count: 3192
Extent:

XMin: -14842598.7710571
YMin: 2023662.5156
XMax: -7260385.6561
YMax: 8022002.20690514
Spatial Reference: 102100 (3857)

Layer: USA_CountyGeoJSON_objects (ID:0)
Count: 28