The Tonkawa are a Native American tribe indigenous to present-day Oklahoma. Their Tonkawa language, now extinct, is a linguistic isolate. Today, Tonkawa people are enrolled in the federally recognized Tonkawa Tribe of Indians of Oklahoma. The Tonkawa's autonym is Tickanwa•tic (meaning "real people"). The name Tonkawa is derived from the Waco tribal word, Tonkaweya, meaning "they all stay together". The Tonkawa tribe operates a number of businesses which have an annual economic impact of over $10,860,657 (as of 2011). Along with several smoke shops, the tribe runs 3 different casinos: Tonkawa Indian Casino and Tonkawa Gasino located in Tonkawa, Oklahoma, and the Native Lights Casino in Newkirk, Oklahoma. The annual Tonkawa Powwow is held on the last weekend in June to commemorate the end of the tribe's own Trail of Tears when the tribe was forcefully removed and relocated from its traditional lands to present-day Oklahoma. Scholars once thought the Tonkawa originated in Central Texas. Recent research, however, has shown that the tribe inhabited northwestern Oklahoma in 1601. By 1700, Apache and Wichita enemies had pushed the Tonkawa south to the Red River which forms the border between current-day Oklahoma and Texas. In the 16th century, the Tonkawa tribe probably had around 1,900 members. Their numbers diminishes to around 1,600 by the late 17th century due to fatalities from new infectious diseases and conflict with other tribes, most notably the Apache. In the 1740s, some Tonkawa were involved with the Yojuanes and others as settlers in the San Gabriel Missions of Texas along the San Gabriel River. In 1758, the Tonkawa along with allied Bidais, Caddos, Wichitas, Comanches, and Yojuanes went to attack the Lipan Apache in the vicinity of Mission Santa Cruz de San Sabá, which they destroyed. The tribe continued their southern migration into Texas and northern Mexico, where they allied with the Lipan Apache. In 1824, the Tonkawa entered into a treaty with Stephen F. Austin to protect Anglo-American immigrants against the Comanche.