With no explanation, label each line with "O", "location-mountain", "location-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
In
1861
,
cattle
were
being
driven
over
the
Sierras
to
feed
the
mining
boon
town
of
Aurora
.
In:O
1861:O
,:O
cattle:O
were:O
being:O
driven:O
over:O
the:O
Sierras:location-mountain
to:O
feed:O
the:O
mining:O
boon:O
town:O
of:O
Aurora:location-other
.:O