yes that is the extent of the REST service. here is what the REST page looks like through ArcGIS Services Directory:
basemap_cache (MapServer)
View In: ArcMap ArcGIS Explorer ArcGIS JavaScript Google Earth ArcGIS.com Map
View Footprint In: Google Earth
Service Description:
Map Name: Layers
Legend
All Layers and Tables
Layers:
barren (0)
ortho_1-1_1n_s_ky009_2010_1.sid (1)
Tables:
Description:
Copyright Text:
Spatial Reference: 2247
Single Fused Map Cache: true
Tile Info:
Height: 256
Width: 256
DPI: 96
Levels of Detail: (# Levels: 😎
Level ID: 0 [Start Tile, End Tile]
Resolution: 257.881076388889
Scale: 297079
Level ID: 1 [Start Tile, End Tile]
Resolution: 128.940104166667
Scale: 148539
Level ID: 2 [Start Tile, End Tile]
Resolution: 64.4696180555556
Scale: 74269
Level ID: 3 [Start Tile, End Tile]
Resolution: 32.234375
Scale: 37134
Level ID: 4 [Start Tile, End Tile]
Resolution: 16.1171875
Scale: 18567
Level ID: 5 [Start Tile, End Tile]
Resolution: 8.05815972222222
Scale: 9283
Level ID: 6 [Start Tile, End Tile]
Resolution: 4.02864583333333
Scale: 4641
Level ID: 7 [Start Tile, End Tile]
Resolution: 2.01388888888889
Scale: 2320
Format: JPEG
Compression Quality: 75
Origin:
X: -121000700
Y: 152113100
Spatial Reference: 2247
Intial Extent:
XMin: 1455768.96629259
YMin: 1753655.99007773
XMax: 1715713.09129259
YMax: 1967948.06691259
Spatial Reference: 2247
Full Extent:
XMin: 1502400.36474015
YMin: 1757922.13623097
XMax: 1669081.69284502
YMax: 1963681.92075935
Spatial Reference: 2247