The USGS quad is in error:
http://listsofjohn.com/peak/22222
Bottleneck Peak is not the flat topped mesa, it is the tower 6235 to the northeast, which actually does resemble a bottleneck (the BLM sign also correctly identifies the peak):
The mesa is sometimes referred to as Bottleneck Mesa, but the USGS map is in error.
There are many sources to this including Steve Allen's book on the San Rafael Swell, Eric Bjornstad's Desert Rock, Selected Climbs in the Desert, etc.
Anyway, to quote Desert Rock, page 223:
Bottleneck Peak is the commanding landform 6235 in elevation (1900m) to the right of the road when viewing south from the San Rafael River. Two miles (3.2 km) from the river the peak is identified by a sign and is obvious to the west. Bottleneck Peak is mislocated on the USGS Bottleneck Peak Quadrangle (7.5 minute topographical series). It true location is designated 6235 on the map.
Also see all google photo searches for the peak:
https://www.google.com/search?q=bottlen ... IQ_AUIBigB
See also here:
https://books.google.com/books?id=uPs1M ... mb&f=false