When I was young and the internet still only dial-up, I had an idea for a Future Farmers of America chapter fundraiser.
A chapter in, say, Wray, Colorado, could poll its members' parents and friends and come up with a list of landowners who allowed hunters on their property (for free or for a small trespass fee).
This list could be photocopied into a little booklet and sold at the Chamber of Commerce or fundraising events.
Maybe someone did something like that, somewhere. But now Colorado Parks & Wildlife has done something a little bit similar.
I picked up this 6x9-inch spiral bound book last month at the High Plains Snow Goose Festival. It is for southeastern Colorado — there are similar books for the other three quarters
There is an overall "birding trail" page at the CPW website.You can also download the books as PDF files or pick up durable printed copies (if they are in stock) for free at regional offices.
You will find descriptions of accessible sites such as public parks, state wildlife areas (all adults must have a hunting or fishing license or SWA pass), and others, and also farms and ranches that engage in eco-tourism, offering hiking, camping, birding, and in some cases hunting access as well.
Fees are not given, but there is contact information.
There are also auto-route guides, such as this excerpt for Cordova Pass in southern Colorado.
It's a lot of good information in one place, and you should have it if you live in or travel through Colorado for outdoor recreation.