The bulk of Hasenclever Hill is in New York, but the true summit is in New Jersey.
The true summit lies at the right most end of the mountain's crescent shaped top and is defined by a glacial erratic and a nice bald spot to relax. During the summer months, the summit is surrounded by blackberries and blueberries.
If you follow the mountain's summit curve into New York State, there is an OUTSTANDING southerly view, called "Black Rock", sweeping from Big Beech Mountain all the way to the Ramapos. Black Rock is technically a few feet over the border from New Jersey, but the viewshed is entirely New Jersey.
Parked at Ringwood Manor and followed the Hasenclever Iron Trail west. The trail was rerouted in 2020 around the north side of Hope Mountain through the col between Hope Mountain and Hasenclever Hill. While descending the west side of the col between Hope Mountain and Hasenclever Hill we followed a well defined ATV track which climes the south side of Hasenclever Hill. A heard path off of the ATV track leads to the top of the eastern peak of Hasencvever Hill, which is the summit. On top there is a large boulder and a view looking east towards Blue Lake. We then bushwhacked west along the top of the Hasenclever Hill ridge for ~1/3 mile to reach the west peak. This is where the Black Rock viewpoint is located, which is probably one of the best viewpoints in the NJ Highlands*. The view looks south and the Ramapo Mountains, Windbeam Mountain, the Wyanokies, Long Hill, the Monksville Resevoir, Bearfort Mountain, and Big Beech Mountain can be seen. A well defined woods road (this woods road is not marked on the NYNJTC Map (at least not the 2012 edition)) descends northwest and links with Beech Road in Sterling State Forest. We then followed woods roads to the south of Hasenclever Hills marked on the NYNJTC map to link back up with the Hasenclever Iron Trail and head back to Ringwood Manor. The total trip was around 7 miles I think.
*the Black Rock is technically in NY but the entirety of the view is of NJ.
Parked on Beech Rd and took the Hasenclever Iron Trail for a little bit before taking a woods road that went to the NJ/NY border. I ended up bushwhacking up the steep western side of the mountain and intersecting a woods road which took me to the overlooks. No views today so I continued on to the summit. From the NYNJTC maps there appears to be a woods road that goes along the summit but I couldn’t find anything so I bushwhacked to the highest point which looks to be the glacial erratic. From there I followed a faint path down the mountain and took the Hasenclever Iron Trail back to the car.
Backtracked down Big Beech and took the woods road that links up with the yellow trail. Other than the blazes, the yellow trail really isn't any different than the woods road; it was very wet and muddy with tons of ruts. Took the yellow trail for a while and then followed a pretty twisting network of woods roads. That stopped near the base of Hasenclever Hill and it was a straight shot up from there. Pretty decent views from the top. On my way down I went off the wrong side of the mountain and had to deal with some pretty steep thorny sections.
I did the same hike as Peter D. Like him, I lost the ATV at the top of the first ridge but was able to find another when descending from the summit. Lots of trash on the south side of Hasenclever Hill. The trail goes by Jehovah's Witnesses World Headquarters at the south end of Blue Lake. It pretty impressive and looks like a modern resort-conference center but not a soul in sight!
We set out from Blue Lake in Sterling Forest and followed woods roads to the Black Rock viewpoint. What a great view and a sweet spot for a break and picnic! From there the woods road seemed to have disappeared but the short bushwhack to he southerly most portion of the ridge was easy going. A few Interesting erratics kept the scenery even more interesting. From the high point we bushwhacked a north then northeast route back to Blue Lake and past an old abandoned mine.
All in all, this was a really nice little hike!