After exploring among pueblos in New Mexico, Antonio de Espejo reached the Pecos River southeast of Santa Fe in 1583 and named it Rio de Las Vacas, or River of Cows, for the abundance of buffalo. On his return route to Mexico he followed the river to near the present town of Pecos, then Jumano Indians led his party to their camp on Toyah Lake. He then went down Toyah Creek and through the Big Bend. Although Espejo was the first to explore the Pecos, Castano de Sosa, traveling into New Mexico in 1590, was the first European to travel the river's full length.