York, the only name given for Captain William Clark's slave in the journals of Lewis and Clark, played an important role in the success of the Corps of Discovery. The journals refer to him as a black slave to Captain William Clark and document that he tended to the sick, hunted and fished for food, and contributed to wildlife observation. His muscular appearance was curious to the Native people the Corps encountered, and he gained their respect, which helped the expedition. He was given an equal vote in the Corps' decision to winter at Fort Clatsop on the Pacific Ocean in 1805. After the expedition, York requested his freedom, citing his contributions to its success, but William Clark did not successfully negotiate that freedom until almost five years later. York remained a black man in a world of slavery and segregation, and history has not fully revealed how successfully he was able to function in a society still developing its ideals of equality and freedom. Two places in Montana were named in his honor: Yorks 8 Islands in Broadwater County and Yorks Dry River, now Custer Creek, in Prairie County along the Yellowstone River.