"We are extremely pleased to be able to acquire Ryane,” Rangers general manager Glen Sather said in a statement. "He is a unique combination of size, skill and toughness. His strong leadership and character make him a tremendous addition to our organization on and off the ice."
San Jose acquired New York's second-round selection in the 2013 NHL Draft, the Florida Panthers' third-round selection in 2013 (previously acquired by New York) and a conditional second-round selection in 2014.
"Ryane is a tremendously respected player and teammate, and an individual of outstanding character,” Sharks general manager Doug Wilson said on the team's website. “These deals involving players who have spent a substantial amount of time in and contributed much to San Jose are difficult, but it's also important for us to get value for a player who is set to be an unrestricted free agent."
Clowe (6-foot-2, 225 pounds) does not have a goal in 28 games this season after scoring at least 17 in each of the previous four. He had a career-high 62 points in 2010-11.
The 30-year-old can become an unrestricted free agent this summer. He debuted in 2005-06 and has played all of his 423 career games with the Sharks.
He leaves San Jose ranked ninth on the team's all-time points list with 271 (101 goals, 170 assists).
If Clowe re-signs with the Rangers or the team wins two playoff rounds, the 2014 pick remains New York's second-round selection. If neither occurs, the pick becomes New York's fifth-round selection.