Mined cryptocurrency should be treated as earned income at the time the coin is created.
It will also be subject to capital gains / losses at the time of disposition.
You should enter the amount of mined cryptocurrency within step 3 "other transactions" in CryptoTrader.Tax. By including the type of crypto mined and the date and time it was mined, the tax engine will automatically associate the fair market value of that crypto with the date and time that it was acquired.
Our blog article on cryptocurrency mining taxes can be read for a more detailed understanding of how this works.