Hallalhotsoot, also Hal-hal-tlos-tsot or "Lawyer"[1] (c. 1797–1876) was a leader of the Niimíipu (Nez Perce) and among its most famous, after Chief Joseph.

[3] His name appears as early as 1836 in a meeting with Marcus Whitman, and received the nickname "Lawyer" for his eloquence.

[4] After a group of missionaries arrived at Whitman Mission Station in Waiilatpu in 1838, Lawyer taught Asa Bowen Smith the Nez Perce language,[3] from which Smith developed a grammar and dictionary entitled Grammar of the Language of the Nez Perces Indians.

After gold was discovered in Pierce in 1860, Lawyer agreed to new cessions of land in the Treaty of 1863,[8][9] in 1868, which Old Joseph (c.1785–1871) did not accept and considered it a betrayal.

It carved the 300-foot (90 m) deep Lawyer's Canyon, between Ferdinand and Craigmont, and flows east to its mouth at Kamiah.