PLT OF AN SMA SEL ENTERED CLASS C AIRSPACE WITHOUT FIRST CONTACTING THE CTLING TRACON ATC FACILITY.

Narrative

I WAS ENRTE FROM FRENCH VALLEY; CA; ARPT (F70) TO LAVERNE; CA; ARPT (POC) CRUISING AT 3000 FT MSL. AS I APCHED CORONA ARPT (L66); I CONTACTED CHINO TWR RATHER THAN SOCAL APCH; WHICH WOULD HAVE BEEN APPROPRIATE FOR THE ALT I WAS AT. CHINO AIRSPACE EXTENDS UPWARD TO 2699 FT MSL AND ONTARIO CLASS B BEGINS AT 2700 FT MSL. THIS SHOULD HAVE BEEN OBVIOUS TO ME AS I HAD THE TERMINAL AREA CHART (LAX) OPEN ON MY LAP. IT WAS AN EXCEPTIONALLY CLR DAY WITH 30+ MI VISIBILITY THROUGHOUT THE LOS ANGELES BASIN AND CONSIDERABLE VFR TFC COMPARED TO A MORE NORMAL; HAZY SUNDAY; AND I WAS PREOCCUPIED WITH THE POTENTIAL FOR MIDAIR CONFLICTS; ESPECIALLY IN THE VICINITY OF CORONA ARPT WHICH IS UNCTLED. IT WAS FOR THIS REASON I WAS AT 3000 FT RATHER THAN 2000 FT OR 2500 FT. HOWEVER; THIS DOES NOT COMPLETELY EXPLAIN WHY I DID NOT NOTICE SOMETHING SO PLAINLY MARKED ON THE CHART. I CONTACTED LAVERNE/BRACKETT TWR 10-12 MI OUT. AT THAT TIME THE CTLR ASKED ME IF I HAD BEEN TALKING TO SOCAL APCH. I TOLD HIM I HAD BEEN TALKING TO CHINO TWR. IT WAS THEN THAT I REALIZED MY MISTAKE. THE CHINO CTLR WAS VERY BUSY AND DID NOT NOTICE THAT I WAS ABOVE HIS AIRSPACE EITHER.