To find Whale Peak you have to find Hwy 78 that connects Escondido and the Salton Sea. I came from Escondido and about 11.8 miles east of Julian there is a signed junction with the Great Overland Stage Route on the south side of the Highway. Follow this road 4.5 miles through Shelter Valley to the Anza Borrego State Park. As soon as you pass the sign for the park there is a dirt/sandy road on the left or east side of the road. Take this road and stay on the road. Off road excursions are not permitted and it looked like a good place to get stuck in the sand anyway.
You can see Whale Peak ahead to the right. The road will take you to a saddle on the north side of Whale Peak. The road gets rocky at 3.6 miles and you probably need 4WD and High Clearance to get through this part. At 5.5 miles from the paved road you get to the highpoint of this sandy road. There is a spur road to the right towards Whale Peak. Take this road .3 mile to its end. There is parking here for 4-5 cars. The trail head is straight ahead up the drainage. Elevation at the trailhead is about 4,110 ft. If it rains in the area, this access road may be impassable.
The route to the summit of Whale Peak from the trailhead is easy to follow if you follow the ducks. From the parking area, walk up the drainage and climb the steep ravine that must have some beautiful waterfalls after a torrential rain. At the top of this rocky wash, after you climb about 250ft, there is a trail and it levels out. Someone spent a lot of time putting up ducks/cairns to mark the trail all the way to the summit. Follow them. The trail will probably be obscure after a rain, but when I followed it, there were many boot tracks on the trail to follow.
Look for the ducks ahead and pick your way between the rocks and cactus to the next duck. After the initial steep climb from the trailhead the trail isn’t very steep anywhere until you get to the last slope up to the summit ridge. About half way to the summit another trail joins the one you are on as it comes up the south side of Whale Peak from the petroglyph area.
Once up the steep slope near the summit, you still have to walk about a quarter mile across the summit plateau to the highpoint. There is a register to sign, benchmarks to see, and boulders to climb. No big deal with the boulders, just walk around the back of them for easy access to the top.
When hiking, the ten essentials are always required. No technical gear is required. Be sure to bring water in the summer and wear a hat and sunblock. Take your camera and enjoy the views. Don’t be surprised to see a snake or two since this is the desert. Take precautions.