Explored the Concho River, 32 miles north of here, gathering information on Jumano Indians and searching for pearls, 1650. Setting out from Santa Fe, Capts. Hernan Martin and Diego Del Castillo traveled about 600 miles to the Jumano territory, where they stayed for 6 months. Further travels took them to the edge of the Texas nation, where they obtained the first information definitely about the tribe that gave Texas its name. The "discoveries" of their journey -- pearls and the Texas nation -- sparked later important Spanish expeditions to East Texas.