Amount of maintenance running for June HIM

How much it takes to maintain current fitness depends on how much fitness you currently have. So there's no general rule. Your logs indicate 10 runs in the past 4 weeks (2-3 times/week), with a longest run of 6 miles. Does this correspond to the level that you want to maintain? Unfortunately, the guideline on having the long run be no more than a third of the weekly total should probably be taken seriously, even in 'maintenance', so you should choose what kind of long run you want, and then multiply that by 3 to get a weekly mileage goal.