Marines in large numbers working out at municipal park in Sherman Oaks, CA. Estimate 50+ strong. Picture shows approx 25 doing calisthenics while an equal number ran laps around running track. Military are often seen at this park. Included are the Army Reserves nearby, plus a Navy Seal try-out team where they run potential recruits through a physical workout, Navy regulars using the pool, and Marines in squad size doing calisthenics.
Only the Army Reserves and Navy Seal recruitment try-outs make sense in terms of regular appearances. There is no Naval base in Los Angeles county, and no Marine facility within the L.A. metropolitan vicinity.
The regular appearance of military using that park began after the 2016 election. If the military were used for any domestic purpose in the Los Angeles region, they would need a location for staging. a municipal park is an ideal location. This large Sherman Oaks park in particular is ideal for setting up a defensive perimeter, and is close to the two major freeways - 101 and 405. It is also near a hospital corridor. The Van Nuys airport is a short distance away. The Sepulveda Basin is also a large open space nearby that could be used for staging.
Speculation: US military are making themselves a familiar sight at this park for a reason. The Marines I saw today working out were hardened, fit, all business, and loud. Trust me when I tell you that the locals notice whenever the military show up. The people who use that park early in the morning include the local professionals who run things. Word spreads.
Sorry for the crap image. Pic taken with an old phone. Marines wearing their black t-shirts with "PAIN Is Weakness Leaving The Body" printed on the back.