Hiked from Grouse Vista TH. 3 miles to Silver Star. We continued about 1 mile further and few hundred ft down to the arch.
Flowers are in full bloom. Mosquitoes is not an issue. Trail is full of rocks. This is the least favorite of mine comparing to Ed's Trail and Bluff Mt Trail.
https://www.oregonhikers.org/field_guide/Silver_Star_Mountain_via_Grouse_Vista_Hike