The major presence for the protection of the West Coast WAS the Pacific Fleet at Pearl Harbor. The fleet had moved almost 2 years previously to Pearl full time. Previously the battle force (battleships and escorts) had spent much of the year in California with San Diego as the main base, while the scouting force (carriers, most cruisers, escorts) split time between Cali and Pearl with the entire fleet meeting at Pearl in the summer to exercise.

Thus the majority of the strength to defend the Eastern Pacific was indeed at Pearl Harbor on December 7th. With some major exceptions.

The Battleship Colorado was in Brementon undergoing a refit, and the Carrier Saratoga was in San Diego to pick up her air group after just leaving refit. Saratoga gathered her squadrons and a few escorts and departed rapidly to Pearl where she, her sister Lexington, and the Enterprise would attempt an eventually aborted mission to lift the siege of Wake island int he second half of December 1941.

Meanwhile the Enterprise and her task force of cruisers and destroyers was returning from delivering additional aircraft to Wake Island and Lexington was doing the same from Midway.

This list which despite being wiki is useful and accurate to all my knowledge shows the order of battle of the fleet at Pearl Harbor, which is USN planning was the primary defense of the West Coast and thus valuable to consider. https://en.wikipedia.org/wiki/Order_of_battle_of_the_Attack_on_Pearl_Harbor