I am collecting links to fossil, rock and mineral collecting laws/codes/rules in the US Forest Service lands and other Federal lands. LINK The default is that you are allowed to collect most invertebrate fossil in US Forest Service lands unless it is in written plans or rules that prohibit it. Always ask US Forest Service managers ahead of time if collecting is allowed and the written rule or plan that allows or prohibits it.
Please let me know if you have any additional info to add to my collection. I find the actual rules or laws most useful.
Read sections 291.1 to 291.12 of the applicable code from the Code of Federal Regulations: link Definition of “casual collecting” and its sub parts especially important. Rest of code should be read before collecting.