After the free trial ends, the annual membership fee for PRO will kick in if auto-renew is on. Auto renew is on by default (which is standard in the app industry) and can be adjusted at any time.

A one year membership of The Dyrt PRO is currently $35.99 and includes features such as:

Campground discounts - up to 40% off and no booking fees
Offline access
PRO Maps (BLM, & USFS)
Road Trip Maps and more!