Then in 2012 I started noticing new signs on the Rail Trail in Dundas announcing that it was now free to walk or cycle into the valley (though I am sure many of those using the rail trail were not paying previously)
As the HCA puts it on their web site:
Beginning in 2012, the walk-in and bicycle entry fee has been removed in the Dundas Valley. All visitors to the Dundas Valley are encouraged to purchase a HCA Annual Membership Pass to help support the maintenance and operational costs of the area. The HCA does not receive funding from the province of Ontario or the City of Hamilton for the operation of its conservation areas.If you are only using the Dundas Valley trail system, there is no longer a requirement to pay if you walk or ride in. I will likely continue to hold a membership for the HCA, since I love the work they do, and I'd encourage you to join as a paying member in support of such a wonderful place.