I decided that Utah Democrats, if they hypothetically controlled the State Senate, which possibly won't happen in my entire lifetime, would decide to draw as many swing seats as possible rather than safe seats. In a GOP wave, Dems could fall to 1 or 2 seats, but it's not like they'd have much power anyway; their goal would be to keep 1/3 to help a less conservative governor like Herbert check a very conservative legislature.
Further, like in many safe Republican states, anything below R+5 is at least a Tossup and possible Lean D. I only used 2008 results, and tried to keep district numbers the same where possible. Incumbency was not taken into account.
1st (gray): Ralph Okerlund (R) R+35
This sprawling rural district would be among the most Republican state senate districts in the country. It does include some suburbanized parts of Utah County as well.
28th (dark blue): Casey Anderson (R) R+32
The somewhat sizable town of Cedar City is the main population center here.
29th (white): Steven Urquhart (R) R+32
St George and a couple suburbs.
27th (light green): Kevin Van Tassell (R) and David Hinkins (R) R+37
Even redder and extremely rural. Having visited Utah exactly once, for about five days (I have liberal Jewish relatives in Sandy!), I can't profess to know anything about who'd win this primary. But the Dem would get below 25% in the general.
17th (purple in NW): Peter Knudson (R) and Scott Jenkins (R) R+34
Another incumbent on incumbent matchup in a rural district.
25th (pink): Lyle Hillyard (R) R+27
Logan makes this district slightly bluer than the others, if that means much.
6th (teal): OPEN R+3
R+3 in Utah means Tossup to Leans Dem. This is my favorite district that I drew; a Dem seat that doesn't enter Salt Lake County. One concern would be Park City electing someone too far to the left for this district. However, Carbon County is ancestrally D (Pinto Dems, like in Arizona), and they're probably much more moderate to conservative.
What does this show so far? Utah has a very small rural population. In fact, after drawing every state in DRA, Utah ranks 6th among the 48 contiguous states in terms of population in urban, suburban, or large town areas, at 17.7%, ahead of only New Jersey, Maryland, Nevada, Arizona, and Florida.
Now on to more populated areas.
Davis and Weber Counties:
19th (ugly green): Allen Christensen (R) R+24
North Ogden and some rural areas in the mountains. Not much to see here.
20th (pink): OPEN R+24
Roy, Hooper, Clinton, West Point.
21st (brown): Jerry Stevenson (R) R+24
This area is very consistent in its PVI. Clearfield, Layton, and Syracuse are contained here.
22nd (medium blue): Stuart Adams (R) R+27
A slightly redder area. The other half of Layton plus Kaysville and Farmington.
18th (orange): Luz Robles (D) vs Jon Greiner (R) R+5
My other favorite; Dem/swingy areas of Ogden were commbined with part of Salt Lake City. In Utah, this would probably be a tossup, although since Robles is a SLC Dem she's probably more liberal.
16th (dark blue): Curt Bramble (R) R+31
The Provo district.
15th (orange): John Valentine (R) vs. Margaret Dayton (R) R+34
I just realized it now, but the UT State Senate is nearly entirely male. This district is basically just Orem, Provo's more conservative sibling.
14th (puke): OPEN R+38
The less well connected of Valentine or Dayton could run here in this insanely red district. American Fork, Pleasant Grove, and Lincoln are the main locales, along with Alpine and Highland.
13th (peach): Mark Madsen (R) R+36
To my surprise, this is not the former Stanford star/Los Angeles Laker/Minnesota Timberwolf, but another Mark Madsen. Also the home of Mia Love; when she loses the UT-4 primary, as is likely in my opinion, she could end up here in a couple years.
And now...Salt Lake County!
23rd (pale blue): Todd Weiler (R) R+3
I'd call this Tilt Dem and possibly Lean. Swingy districts = Dems in Utah, much like Kansas (except they have moderate Republicans and Utah doesn't). Salt Lake City and a couple very red suburbs
7th (gray): Ross Romero (D) R+2
Same story, except a Dem incumbent means Leans D.
8th (periwinkle): Karen Morgan (D) R+3
East Millcreek, part of Holladay, Cottonwood Heights, and some of Sandy. Basically places I didn't realize you could make a swingy district out of.
4th (red): Patricia Jones (D) R+2
Millcreek, East Millcreek, Murray, Holladay, and a few precincts in other suburbs.
9th (light blue): OPEN R+5
I am going to call this a Tossup. It's not contiguous due to a large precinct I would split on a real map, and is one of three baconmanders.
10th (pink): OPEN R+2
Another bacomander, Leans Dem.
2nd (dark green): Ben McAdams (D) R+2
The third baconmander.
5th (light green): Karen Mayne (D) R+3
West Valley City, Kearns, and Taylorsville are all you need for a Dem seat.
11th (gray): Wayne Niederhauser (R) vs. Aaron Osmond (R) vs. Howard Stephenson (R) R+26
I predict Osmond wins due to name rec from his family.
24th (purple): OPEN R+18
Tooele didn't have its own Senator despite its size. I fixed that, probably.
12th (black): Daniel Thatcher (R) R+4
Tossup seat in West Valley City.
So the total: 16 R, 10 D, 3 T
In a Dem wave: 16-13 R
In a GOP wave: up to 29-0 R
But in Utah, that's a risk Dems should be willing to take.