I refer you to my stack entitled a Jewel of Nature Inside the City. The Grasslands trail is one of the easier trails in Mission Trails Regional Park. Here are some of my photographs from a recent hike along this 2 mile trail.
San Diego River
Pool along the San Diego River
All images above taken with Olympus OM D E-M10 Mark III, edited with Lightroom CC.
Jon Pinter
The last photo is especially interesting. It’s an explosion of yellow dots. Almost like Pointillism or Impressionism in painting. It’s like a swarm of bees. I can almost hear it.
I believe it is a weed called mustard and is bright yellow.