Conda Environment - Using base environment interpreter

I use Conda to manage environments.   I created a new Conda environment (using Conda) without specifying a specific Python version - defaulting to the version in the base.   When I try to set the interpreter in the Project Interpreter in Pycharm, I navigate to the appropriate Conda environment, but because it does not explicitly have a version of python in it, I can't specify the environment.  

I'm running Win10 and the latest Pycharm and Anaconda - using Python 3.6. 

I have tried specifying the interpreter in the base Anaconda env, but then I can't seem to get imports into the new environment to be recognized.  

Both PyCharm and Anaconda are installed for all users.  

I've looked at the docs as best I can and searched with Google.   There is clearly something simple I'm not understanding and I'd appreciate any help.

Thanks,

  -Don