YES! YES! a million times yes!
It's your introduction to Dartmouth. It's 2% (if that) about the outdoors, and 98% about meeting your fellow first-years, getting to know 2+ upperclassmen, and learning more about the school from students without the administration PR
If you read all the testimony about trips, you get a sense of what it's all about. I'm biased, I led three trips when I was in Hanover, but it's a TON of fun (for everybody, even people who generally don't like the outdoors, or have never spent time in the woods before) and a really low-key way to meet people and start integrating yourself into the wonderful world of Dartmouth.
If you ask current (and past) students about their first year trips, almost (there are exceptions to everything) everyone will give you highly positive reviews and memories from their trips. DOC First-Year Trips: Dartmouth College's Outdoor Orientation Program