You can also order the Ontario license online from Wally's Bait & Tackle (which you can link from LSC Muskie Shop. I think orders go out on Thursdays, and you'll get them about the following Tuesday.
Enhanced driver's license is the easiest way to get crossing credentials, which you can apply for at many Sec. of State offices (state website has a list for each county online). There's also the Nexus card, which is good for a couple more years, but has a more involved application process.
I don't think you need these credentials just to fish Canadian waters from a boat if you don't dock or make contact with other boats, if I recall correctly. Dunno about anchoring. Someone correct me if I'm wrong here, but I plan on waiting until my enhanced license comes in anyway.
Could save lots of gas if you want to launch from the Canadian side, as I plan on doing once my enhanced license arrives.