Phil suggested that I conduct a 'stick board' test to count the mites. I'll use Apigaurd, a chemical treatment that is safe for the bees and humans. This will knock out some of the mites and allow me to count the dead ones to give a rough estimate of the level of infestation.
After that, my plan of attack is as follows;
First, I'll be installing a screened bottom board to help keep mites that are groomed off the bees from crawling back up into the hive. The mites fall down through a screen and cannot physically crawl back into the brood chamber where the bees live.
Second, based on the test results and mite count, I will either dust them with powdered sugar (this encourages grooming and the loosening of mites), or I'll go ahead with a full chemical treatment.
Third, I'll continue to test and count mites to monitor levels.
After about four days of research, I've realized that mites are a factor that most beekeepers have to deal with. Levels can be controlled through various chemical and mechanical methods. It seems that the key is early detection and monitoring. So far, I feel a little ahead of the curve and feel like I caught it early enough.
I can't stress enough the importance of having good resources to lean on. Thank you Phil for your prompt response (even on a holiday).