Recreational & Family - Locking Bike in Parks and Woods

I've recently taken up geocaching (GPS-based treasure hunting of hidden tupperware containers) and my preferred method of transportation from cache to cache is my Trek 7.2FX. Often, I need to hike a bit off the trail into some brush or woods in order to retrieve a cache, but I cannot take my bike with me. I need some way to lock my bike up for 10 or 20 minutes, but I'm not sure what kind of lock to get.

I would be locking my bike in parks and woods in a suburb outside of Toronto. Sometimes, these areas are completely deserted and other times they have light pedestrian and bike traffic. There are no convenient signposts, bike racks or locking rings, so I'm concerned that I'd have trouble finding something to use a U-lock with. A cable lock might be better, since it could easily wrap around a tree trunk, but someone with a bolt cutter could be off with my bike in seconds. However, I'm not sure if anyone would be walking around with tools looking for bikes to steal in these areas. A heavy chain lock might provide the strength of a U-lock and the versatility of a cable lock, but it would be very heavy and I'd have to carry it in a pannier.

Your advice and recommendations would be greatly appreciated!

Some options to help deter theft are to not only lock the bike but take the seat and front wheel with you. A little bit of a pain, but I am guessing the thieves will likely be looking for a target of opportunity. The less hassle your bike is to take the greater the chance it will be taken. If they have to walk away with some half assembled bike that they then have to find a wheel and saddle for to sell it, they might keep looking for an easier target.

I'd probably go with a cable lock. You're right, I don't think they would be walking around with bolt cutters.

I'd lock it with a U-lock and not worry too much about securing it to an object. You're not gone for long, there are not many people (thieves) around, and the thief would have to carry your bike. A trail is different from a street corner. The thief cannot just throw the bike in the back of a van and drive off.

I would be sure to lock it to a tree at least. Otherwise it'll disappear with the first bum that shows up. It's unlikely someone is walking with a saw too. But, knowing the folk who live around Toronto, I'd say your bike is on borrowed time. Get ready to kiss it goodbye.

U-lock around the frame and rear wheel. Cable from U-lock around tree. You dont need to get the heaviest cable. Even if they can cut the cable, the U-lock will still prevent them riding the bike.

Under similar but presumably more crowded circumstances (California national forests, mostly), I've used a fairly heavy cable with a padlock, around a stout tree trunk. I also leave the bike a few yards off the trail, rather than right where everybody who passes will see it, and try to lay it flat on the ground rather than standing proudly, gleaming in the sun.
It's possible to be TOO paranoid about stuff like this. It seems to me the chance of anyone coming along with bolt cutters is fairly remote, and if you let the worries spoil your day, your toys are playing with YOU.

I would be sure to lock it to a tree at least. Otherwise it'll disappear with the first bum that shows up. It's unlikely someone is walking with a saw too. But, knowing the folk who live around Toronto, I'd say your bike is on borrowed time. Get ready to kiss it goodbye.

Sadly, I think you can say that about most places, esp urban areas......

Thanks everyone for the advice. I purchased a 15mm thick cable and a U-lock just big enough to accept the cable ends while secured around the frame tube and rear wheel.