Surfdog and anyone else interested-
I came to this area about 20 years ago to fish YNP but find myself actually fishing the PARK less every year. The Shoshone NF and the Beartooth Mt.s provide a more wilderness type experience with its lakes and streams. We have traded somewhat larger Cutts and the Crowds of YNP for the more plentiful, slightly smaller Brookies and a less crowded conditions.
Wyo licenses-You can pick one up in Cooke City- (Yes I know its Montana) at the Bearclaw Bakery or the Cooke City General Store. Top of the World Store in the Beartooth Hwy between Beartooth and Island Lake. Clarks Fork and Spoon on 296 at Crandall also has them. You will probably NOT find internet or cell phone service out there.
There is a book- Fishing the Beartooths. The fishing info is dated and inaccurate but it has lake descriptions. The size of the trout is usually dependent upon the winterkill. The less fish in a lake, the more food, the larger they will be. We find some Ice on parts of lakes in Mid July. The Quality of fishing changes from Lake to Lake yearly. Brookies (up to 8-14 inches) have supersaturated any lake with connecting streams. Wyo G&F have their hands full keeping them from pushing out the Cutts. I've caught 10-12 inch fish in trickles between lakes. We fish lakes that are usually a 1/2 hour or more off the Beartooth Hwy. We encourage people to Catch and EAT all the Brookies they want (legal limits of course).
The Clark's Fork of the Yellowstone is the main stream in the area, with several tribs that contain Cutts and Brookies. If you have access to a float tube or boat/kayak I can put you into some Grayling in a lake. My email is: firstname.lastname@example.org
let me know if you might be interested in outside of the park fishing.
If you check out Tim Wade's North Fork Angler's website from Cody, they describe the Clark's Fork of the Y area and the Beartooth Mountain Lakes.