De Anza and his company attempted to forge onward to the northwest along the estuary but become bogged down in the mire. They traced several streams in exploring the valley and found a road that "runs close to a small range completely bare of trees." On this day's exploration, they came across "six villages, whose inhabitants, not accustomed to seeing us, fled like wild beasts." Many of the native tribes feared De Anza's men, although he notes that "forty heathen have come close to us and I have given them presents." Most likely referring to the Ohlone, De Anza describes local tribes as "not short haired like those from the mission of San Antonio to the port of San Francisco. These of which we are now speaking wear their hair tied up on the very top of their heads where only a piece of thread is to be seen." The land at this time was primarily open oak savannah, populated by valley oaks and California bunch grasses, which are typically distinguished from the European invasive species by their tendency to stay green in the summer. Due to the presence of Indians and elk (which have the same eating and trampling effects as cattle), not many bushes grew in the area. Riparian habitats provided fertile grounds for cottonwoods, sycamores, willows, and ashes to thrive. The current location of the Ulistac Natural Area is the brackish intersection of saltwater wetlands from the Bay and freshwater sources including rivers and groundwater. At the north end of the park, groundwater is only three feet below ground; at the south end, it is ten feet down. In early 1777, Father Thomas de la Pena, Lt. Jose Joaquin Moraga, several soldiers and their families, and a Yuman Indian convert named Marcello established Mission Santa Clara de Asis. Missionaries recruited native tribesmen to work there and converted them to Catholicism. At the end of the year, El Pueblo de San Jose de Guadalupe was established along the Guadalupe River as the first incorporated city in California. Captain George Vancouver, an English explorer, visited the area in 1792. He noted the Santa Clara Indians "building for themselves a range of small but comparatively speaking comfortable and convenient habitations-each consisting of two commodious rooms with garrets over them." In 1799, Marcello and 200 other natives planted three rows of willow and poplar trees to create the Alameda which now connects Santa Clara with San Jose. They dug irrigation canals to divert water from the Guadalupe River to the trees. The Spanish, involved in a war with their colonies, proceeded to convert the Native Americans in the area under the tenet that the natives would fight and defend the California landscape against opposing Spanish forces, thus minimizing military costs while protecting their land. Priests initially brought the Ohlone into the missions with gifts consisting of glass beads, cloth, ribbons and other trade goods given to the head of the triblet or 'captain' in the hopes that the rest of the population would follow their leader. Conversion to Mission life was slow and for the most part incomplete, it also brought with it drastic change to the Ohlone lifestyle. They were required to change their dress, their courting practices, food collection and their living arrangements. Native dress was changed into white wool blouses and scarlet skirts for the women and the men wore long shirts or blankets, ideal clothing for the priests to promote modesty and sufficient to accomplish daily tasks and prayer. In 1818, an earthquake destroyed the first Mission Santa Clara. The new mission was moved to its current site at Santa Clara University. In 1822, the mission was completed; Mexican rule replaced Spanish rule in California. An 1827 census at Mission Santa Clara tallied 1,500 Native Americans, 15,000 cattle, 15,000 sheep, and 2,800 horses. The Indian population rose to 1,800 in 1834, but by 1839, there were only 300 Indians left at Mission Santa Clara.