With no explanation, label each line with "location-GPE", "O", "location-mountain", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
They
are
part
of
an
``
archipelago
''
of
mountain
ranges
known
as
the
sky
islands
that
connect
the
Sierra
Madre
Occidental
in
Mexico
with
the
Rocky
Mountains
.
They:O
are:O
part:O
of:O
an:O
``:O
archipelago:O
'':O
of:O
mountain:O
ranges:O
known:O
as:O
the:O
sky:O
islands:O
that:O
connect:O
the:O
Sierra:location-mountain
Madre:location-mountain
Occidental:location-mountain
in:O
Mexico:location-GPE
with:O
the:O
Rocky:location-mountain
Mountains:location-mountain
.:O