Lot to learn and it's easier to learn locally than trying to learn market trends, values, environmental issues, etc. from afar...or until you have a trusted team set up who can assist you on this. 

On a side note, you should look at the Boulder area specifically, because you have a huge pool of ready tenants and all parts of the city are much more open to progressive (especially environmentally conscious) ideas.

Haven't updated this post in a while, because I have been unable to close on the lots due to environmental issues.

Services you pay for - building inspections, appraisal, survey, environmental, etcIf the seller cannot or will not disclose requested information then you need to figure out why (they just might not have it, or there might be something they are trying to hide).

I own an environmental consulting company and do expert witness work. 

Department of Treasury with usc exceptionState Tax LienLien by USA or Dept of JusticeUS Department of StateOther Federal AgenciesCode Enforcement for debris removal or mowingDemolition or Environmental Based Liens State child support lienBoard of County Commissioners for special assessmentsUtility LiensWater/Sewer Delinquency (only in selected states)County (and/or School/Township) for unpaid taxes@Steve Babiak has also graciously compiled a list of forum posts related to courthouse auction sales below:  http://www.biggerpockets.com/forums/41/topics/6897...

Most recently the Gowanus area has exploded after years of being bad rapped because of pollution concerns with the canal.

My background is in performing environmental due diligence for Private Equity real estate transactions, REITs and other transactions.

Lots of discounts available for upgrading old properties environmentally too.

The county Environmental Dept can help figure out what you are working with there, and what challenges might present themselves , but wells and septic systems are expensive to dig/drill/install/replace, so know what you are getting into there. 3) People often think that because their property is in the south valley or outside of ABQ, or on acreage, that they can do whatever they want with it, but there are usually still CC&Rs that will dictate the type of property, size it needs to be, whether or not a guest house or 2nd dwelling can be added, height restrictions, and so on.