I'm a bit behind schedule now as I took last night of to watch the Game of Thrones season final twice (it's that good). So this and the following posts might be a bit briefer than earlier installments (and their not exactly huge treatises to start with.)
So, the Outdoor Recreation Party (Stop the Greens) position boils down to two main things. One, the Greens are killjoys who stop people enjoying nature, and 2) Government shouldn't tell anyone what to do. The second principle I suspect comes from former party officer David Leyonhjelm, whom you might be more familiar with as Liberal Democrat Party Senator David Leyonhjelm. It would appear that there was some overlap between his participation in the two parties, and there have been suggestions that this was not purely innocent.
So what does this mean policy wise. It means people can do whatever they want in national parks, hunt whenever they like, fish whenever they like, own whatever guns they want, have significantly increase speed limits, let people clear however much land they want, greatly reduced taxes, and so on. I think you can see some of the LDP influenced thinking here.
On the topic of national parks and similar, it feels like they don't quite accept that the reason our national parks are so good is because we limit what people do there, and that if we just let everyone do whatever, then we might not have much to leave future generations.