I was going to drive around via 95 anyways, but thought I would at least look into the option of the ferry. Looks like it's closed until further notice.
http://www.udot.utah.gov/main/f?p=100:pg:0:::1:T,V:2257,
Is this the route you're taking... I-95 to 276?
https://www.google.com/maps/dir/461+W+Harvard+Ave,+Gilbert,+AZ+85233-3254,+USA/Bullfrog,+UT/@37.2419489,-111.0651195,9.5z/data=!4m19!4m18!1m10!1m1!1s0x872ba8fd7ba5d175:0x2e07f4233d5049e8!2m2!1d-111.7996858!2d33.3669832!3m4!1m2!1d-110.2106714!2d37.6760956!3s0x8737aefb6202ea83:0x8815db32d855b528!1m5!1m1!1s0x8737ab2d7b5ea245:0x9683be713c0190f8!2m2!1d-110.71971!2d37.5260988!3e0
Yep, that's it.
It should be around 60 miles further for you guys to go to Bullfrog rather than Halls Crossing. It should be about 40+ miles for either one from 95.