Q.Have A Rocky Soil Slope. Big Gopher Issue. Need Plant Recommendations For Quick Spread, Low Water, Gopher Resistant. Tks Much!!
(Los Angeles). Slope is 50’x 15′ – 20% grade. Soil is mixed with slate/rock. Plyable.

Certified GKH Gardening Expert
Ice plants came up in reader's suggestions of plants gophers avoid. It's a succulent ground cover with small, colorful blooms. Catmint and marigolds have been suggested as plants that repel gophers, but according to university extension publications, they don't avoid plants for long. Gophers are famous for pulling an entire plant down into its tunnel. They get their water from the plants, so they have no need to come above ground. One reference said to remove all vegetation, including weeds. The suggestions for laying wire mesh below ground wouldn't be practical in your case because of the hard digging and size. here is more:
https://www.gardeningknowhow.com/ornamental/flowers/ice-plant/growing-hardy-ice-plant.htm
https://www.gardeningknowhow.com/special/slope-hill/hill-ground-cover.htm
https://www.gardeningknowhow.com/plant-problems/pests/animals/camouflage-gardening.htm
https://extension.oregonstate.edu/news/moles-voles-gophers-dig-garden