Complex sentence: The 1970 U.S. Open was the 70th U.S. Open, held June 18--21 at Hazeltine National Golf Club in Chaska, Minnesota, a suburb southwest of Minneapolis.
Split into simpler sentences: The 1970 U.S. Open was the 70th U.S. Open. The golf tournament was held June 18--21,1970, at Hazeltine National Golf Club in Chaska, Minnesota, a suburb southwest of Minneapolis.