I have the perfect solution for a retired botanist who goes to Blue Mounds often and is concerned about garlic mustard...
I'm sorry but the DNR is not the only group that is lacking manpower. I do (probably too) often go out of my way to pull garlic mustard but if that's all we did, we'd get nothing else done, and it's a losing battle anyways as it's just going to come back in a few years even after total eradication. It's a large park and there are places where it's taking over that are nowhere near the bike trails.
We're facing the real possibility of seeing Holy Schist closed this summer if we don't complete about a 1/3 mile reroute.
If he wants to organize some dedicated GM pulling I would ask him to work with the DNR or Friends of Blue Mounds group. While we share many of the same goals (including invasive plant control), this is more in line with their work. I'm pretty sure they are the ones who have placed blue barrels out on Over Lode to put GM into.