Is smoking cigarettes allowed here?

There are designated smoking areas near the bathrooms. I saw people smoking by the river

Guys smoked all night in our camp with no issues. During the day may be different.

Yes, in designated areas.

I have seen people smoke on the trails. I don't believe its allowed. As someone else stated, there are designated smoking areas by the restrooms.

Yes

In your rv is always safe..

I believe there was a designated smoking area by the visitors' center. There probably were a few others.