Beyond the tent https://www.beyondthetent.com/best-places-for-camping-in-utah/#free has some of the best places to camp
Bureau of Land Management Camping | Bureau of Land Management (blm.gov)
Camping USA http://www.camping-usa.com/campgrounds/utah/
Campendium https://www.campendium.com/utah/free-camping Has free camping sites, mostly in southern Utah
Campgrounds Local http://www.campgroundslocal.com/
Explore Tooele Tooele County’s Picturesque Camping Spots - Explore Tooele County
Federal Recreation http://www.recreation.gov/welcome.do?topTabIndex=Home
Forest Camping http://www.forestcamping.com/index.htm great non-governmental site for camping in the US forest. Also see bottom of http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5370807.pdf for a list.
Free camping sites http://freecampsites.net/ a list and map of free camping sites. Not a lot listed in northern Utah.
Free to Roam Boondocking and camping resources | FreeRoam
Hiker central http://www.hikercentral.com/campgroundstates/ut.html also lists campsites
Hip Camp https://www.hipcamp.com/ a great privately owned camping web site including RV sites and cabins.
LDS camps https://camping.lds.org/list/ mostly for girls camps but usually available in the off seasons and weekends for others, especially May and September.
Sandy City list https://sandy.utah.gov/visitors/summer-activities/campgrounds lists camps within an hour of Sandy
Sanpete County http://sanpete.com/pages/camp
The Dyrt - There are more than 10 when an area selected. The 10 best campgrounds in Utah (thedyrt.com)
Utah State campgrounds Campgrounds & RV Parks | Utah.com
Utah Hiking and Lakes http://www.hikesandlakes.com/utah.html
Utah outdoor activities Utah Outdoor Activities - Resource to the Utah Outdoors
Utah State Parks http://utahstateparks.reserveamerica.com/
U.S. Forest Service - Salt Lake Ranger District campgrounds & picnic areas with Open status https://www.fs.usda.gov/activity/uwcnf/recreation/camping-cabins/?recid=8980&actid=29
Weber County owned parks Parks | Weber County Parks and Recreation | Weber County, Utah (wcparksrec.com)