Free: Contests & Raffles.
As far as I know you’re fine rules wise, but you’re maybe taking a big risk of not owning them, anymore.
I've done it... hide them well. I don't see what the issue would be.
We’ve done it many times. Now we have e-bikes and when we park them we just chain them up through the tire. Most people who are hiked in will not mess with your bikes. There will always be people who complain and claim you are breaking rules regardless in the backcountry. Heck you are more likely to have hiking seed eaters tell you that hunting is not allowed in wilderness areas than will tell you bikes are not allowed on the trail leading to the wilderness, especially if you are near i90.
This is a popular thing at a high buck spot I scouted and my buddy hunted a few years back. Walked past the wilderness boundary sign and there were bikes locked to it and some small dirt bikes in the bushes nearby. We felt like idiots having hiked the 3 miles to the boundary
If you teach em how to ride the bike you don't even need a trailer Glad to hear your trailer worked out. I ride up 3-4 miles 1000ft of elevation gain in about 40 mins. takes me 5 mins to get back to the gate.