There was an old X games ramp in the early 2000's at the Mission Valley YMCA. It was then moved to the Clairemont YMCA skatepark, where it was heavily skated for decades. There's a newer vert ramp there now.
The current ramp is 60' wide, steel frame, and maybe 14' tall; it has extensions on both sides. The old ramp was 13.5', with 14' and 14.5' extensions, a 17' roll-in in the middle, and it was at least 80' wide with a slight corner.
I skated the old ramp many times when I lived in San Diego (2005-2006), and my brother skated it a lot when it as at Mission Valley (around 2000). I've also skated the new ramp many times when visiting. Here's me skating the old ramp in 2011 (note the wrong title of the video):
Of course, the most exciting skateing of the year here is usually the famous Clash at Clairemont. Here's 2019 with the new steel frame ramp.