This is my response to a LinkedIn discussion I thought could be helpful to others. Enjoy.
Start a bit smaller and local to you. Groupon started locally before it got to the point it is it at. Limit the site to your home area and get it to work and succeed there, then expand out. Talk about it on Twitter, Facebook, and more importantly on the trail. Do not market it; live it. If it is a passion you will succeed. At this point do not even worry about search engines and such, you will not displace the top hiking sites for a long time, if ever (just a fact).
Go out and hike, talk about the site, but don't force it on your friends or family. Get flyers and put them up on community bulletin boards (real physical ones). Especially the ones at the start/end of trails. Throw an advertisement in a local community paper. Connect with some outdoor clubs at local colleges.
Give it time and be patient. Your site has a real connection to the non-web world, and that world should be the focus for now. 6 or 12 months down the road if things are going well you can begin web marketing. Web marketing is the same, make it real and personal, the only "ad" or "pushy" marketing you should do is with an online advertising firm (Google AdWords for example).
PS. You may want to consider dropping the ads on the site for now to get people to focus only on the content.