May's one week campground closings in the Valley

This morning opened up campground reservations for April and May. However the first week of May was not available in Upper Pines and the second week of May was not available in Lower Pines. Looks like those these campgrounds will be closed for those dates, yet open before and after those dates. Anybody know why? I heard they were re-paving campground roads in March and April.

I'll answer my own question. Found out from N.P.S. that there will be a road sealing project going on then. It can only be done in warm weather, thus the May dates. They'll try to do it in April instead if the weather cooperates.