Usually, the buildings are listed (if at all) on obscure flyers that
only go to manufacturers, or in industry magazines, etc., or with
realtors that cater to the industrial trade... If you are not a
business or manufacturer of some sort you won't be on their mailing
list.. Local house realtors usually do not get those listings, or if
they did it was 10 years ago and the building is no longer listed...
The best method is to drive up and walk around the buildings.. Often
there will be something posted on a gate or a door with a phone
number...
If the buildings are on the river, get out on a boat, surprisingly they
tend to have signs posted on the river side... Also, asking questions
of locals, like the factory next door, at the donut shop, or the gas
station on the corner, etc. will get you a lead... Even flagging down
the local cops can be a good source of leads... They have to contact
the owners when there is a crime on the property... if the cop is in
a good mood he will have central dispatch rattle up the LEIN machine
and get the owners address, if not he'll just beat the snot out of you
for asking
Another source is the local chamber of commerce.. They often know who
owns local factory buildings...
Another source is the web here... Search on industrial buildings
offered for lease or sale in your area...
And failing ALL that now the truly easy solution follows simply go
down to the county courthouse, ask the clerk to cross reference that
street address to the platt book... They have the name and address of
the owner on file so's they can TAX him!

denny