If your are looking for a company to aerate in the Denver area I highly recommend Mile Hi Aeration. We have been using them almost since they started like 20 years ago. They're reasonably priced, they come out every spring and fall to aerate for us. All my neighbors use them too. You always know when it's time to aerate because you see their signs everywhere! They give us a reminder phone call the night before (thank goodness) The work that was most recently performed was far superior then we have ever experienced and the integrity of the company is totally unparalleled within the industry. The uncompromising dedication of their company is always appreciated!!