Here:
The petition and other materials are here.
Osage Nation v. Kemp
Tenth Circuit Finds Osage Nation Reservation Diminished in Tax Case
Opinion here: Osage Nation v. Kemp, 09-5050 (March 5, 2010)
Briefs here.
Appellate Briefs in Osage Nation v. Kemp Tax/Reservation Disestablishment Case
Here:
Lower court materials are here.
Osage Nation v. Oklahoma Tax Commission — Reservation Diminishment
The Northern District of Oklahoma recently rejected the claims of the Osage Nation that Osage County is Indian Country (news article, via Indianz) — osage-nation-v-otc-dct-order
Here are the materials:
osage-opposition-to-motion-to-dismiss
otc-reply-brief-in-support-of-motion-to-dismiss
otc-supplemental-brief-motion-for-summary-judgment
Turtle Talk 