Rainbow ridge is a good guess. The photo does look like it could be down below Rainbow ridge from the east. But as was rightly pointed out, that peak is far too close to roads. Also, there are higher peaks far closer to Trinity Mountain than a 25 mile radius. Steel Mountain, for instance. The Frank Church certainly has areas which could qualify on the remoteness qualifications. There are another couple of wilderness area with Idaho Batholith granite, however, one of which might be big enough to contain this peak's remoteness. The peak is 7.5 miles from the nearest road as the crow flies. Huckleberry is one of the dominant shrubs in the forests in the photograph.