Do I need to purchase the $30 park pass prior to arriving or can i just purchase it when i arrive.?

You can purchase there the pass, we have payed in cash.

You can buy it ay the gate. They accept cards or cash

Get there at 8:00 to park, otherwise you need to park in the town and ride a shuttle in. It's not really a big deal but count on paying $20 to park in town. Also when you pay at the gate you can also purchase a $80 yearly national parks pass for the family. If you don't, keep your receipt and it will credit your total.

U can purchase at the entrance

I bought anual pass.

You can buy it at the gate. Take the free Springdale shuttle. Once off the shuttle walk across the pedestrian bridge and buy you pass. Unless you have a reservation for camping or for staying at the lodge you can not drive in the park. Parking is limited and expensive, $20-30 outside the park. Unless your staying at any given hotel, motel, lodge, AIRB&B it is advised to park at anyone, they will tow you.

Thanks everyone!

It gets packed super early around 8 for the shuttle line

This time of year i would say 8 or earlier. I was there last week. We got there at 9 and waited 40 minutes for the shuttle.

There is ok.