The airspace for KHII is defined per 74 FR 43029 as class E Sectionals such as skyvector show the area as shaded magenta. which means that this particular flavor of class E begins at 700' and extends to the class A.
That airspace extending upward from 700 feet above the surface within a 6.7-mile radius of Lake Havasu City Airport and within 1 mile each side of the Lake Havasu City Airport 150° bearing extending from the 6.7-mile radius to 13 miles southeast of the Lake Havasu City Airport, excluding that airspace with a 2.3-mile radius of Chemehuevi Valley Airport. That airspace extending upward from 1,200 feet above the surface bounded by a line beginning at lat. 34°42′47″ N., long. 114°29′37″ W.; to lat. 34°42′47″ N., long. 114°12′06″ W.; to lat. 34°23′00″ N., long. 114°12′06″ W.; to lat. 34°17′19″ N., long. 114°32′12″ W.; thence to the point of beginning.
Note particularly
and within 1 mile each side of the Lake Havasu City Airport 150° bearing extending from the 6.7-mile radius to 13 miles southeast of the Lake Havasu City Airport
The rule says that the airspace was created for execution of RNAV approaches. Not sure why the 13 mile rectangle is required for RNAV approaches though since I'm a lowly VFR guy.