I don't promote or share this location as I have only been there twice over my 25 years of observing. However, it is a very good site and outside of some farm houses, no LP and it is very dark. You can stay or camp at the campground LINK 1 and LINK 2, with LINK 2 showing a birds eye view of the campground. You could observe there and during the week it is rather sparse.
A preferred location though is to disperse camp at Curlew National Grassland which is just northeast of the campground. Here are directions to get the dirt road that takes you out to the National Grassland area:
Get on UT-201 E in West Valley City from Bacchus Hwy and UT-85/Mountain View Corridor/N Mountain Vw 25 min (18.4 mi)
Take UT-67 N/Legacy Pkwy, US-89 N and I-84 W to N 18575 W St/S Stone Rd in Box Elder County. Take exit 7 from I-84 W 1 hr 39 min (115 mi)
Take S 23000 W and 21000 W to 20500 W/Hess Rd/Steve Hess Rd in Oneida County
Here's a view from my shared observing site map:
There's a cattle guard right before your turn left as you head north on Steve Hess Rd:
If you use my map
LINK you can see there are a couple of locations to observe from. These were the two I tried about 10 years ago so I don't know what they are like now. Be careful as there are rattlesnakes in the area, I saw two last time I was there.
It's dark there or was, SQM 21.82 to 21.85. You may have a few farms with some light in the distance but not enough to bother you. It is a good site and so I thought I would share. It is about 2 1/2 hours from my home, shorter if your along the northern Wasatch Front from Bountiful to Ogden areas.
Here are some images:
These are images of the campsite at Curlew Campgrounds. During the week or off season you may get 2 or so vehicles there but there are about 20 sites so you can spread out. FYI again rattlers are in the area.
Views from site 1 at Curlew Natl Grassland on my Google Map.
Top two in this set give you a feel or the location and the bottom one is from Observing Site 2 on my map.
Roads are good and as a further fyi, cattle can be in the areas so watch out for them. If you're looking for a nice observing spot just over the Utah/Idaho border check this one out!