Shortest state highways in multiple counties?

[Dirt Roads]

Cheater:  FL-847 is posted for 2.1 miles along NW 47th Avenue in Miami (aka Miami-Dade) up to the Broward County line.  Unfortunately, it continues as a hidden route in Broward County way on up to the Palmetto Expressway (FL-826) in Coral Springs, which is about 20 miles.

Another cheater:  FL-575 runs 2.2 miles from US-301 in Trilacoochee (Pasco County) to the Hernando County line.  Both ends continue as CR-575, which were both downgraded from FL-575 back in 1980.  Total distance for FL-575 and CR-575 is 11.0 miles, which might still be a contender.

Do we count toll roads?  The Mount Dora branch of the Wekiva Parkway (Toll FL-453) runs only 3.36 miles from the mainline Wekiva Parkway (Toll FL-429) to Sorrento Avenue in Mount Dora.

[iowahighways]

Iowa's answer would be IA 316, which is less than 6 miles long but runs through Polk and Warren counties before straddling the Warren/Marion county line.

[DandyDan]

NE S-64A, the spur route into Julian, is 0.48 miles and is on the Otoe-Nemaha County border. The numbered highway which fits the bill in Nebraska is NE 24, which goes through Madison and Stanton Counties and is 10.38 miles long.

[roadfro]

Nevada:

For a two-county route:
SR 342 (the truck route for SR 341) is 3.78 miles from SR 341 near Silver City in Lyon County to SR 341 in Virginia City in Storey County.

For a three-county route:
SR 28 near Lake Tahoe is 16.116 miles from US 50 in Douglas County, passing north through Carson City and ending at the CA state line (continuing as CA 28) in Washoe County.

[paulthemapguy]

Illinois's answer:           
                                                 IL169

Of all the dinky short state routes in Illinois under 10 miles long, most of them manage to stay within the bounds of a single county.  IL-169 manages to straddle two counties, though, at 9.04 miles.

[US 89]

Going beyond 2 counties for Utah... is actually pretty hard to do. Thanks to the nature of Utah's state highway system (not a whole lot of mileage, lots of terrain, and almost no concurrencies) it is surprisingly difficult to get a state highway into more than two counties.

The shortest 3 county route is I believe SR 264. In a span of about 15.3 miles, it begins just barely in Sanpete County, snags the northern tip of Emery, and then drops down into Carbon.

The Utah segment of I-84 is 119 miles; I believe it is both the shortest 4+ county and the shortest 5 county route in the state. It helps to traverse the portion of the state with the smallest counties (a good length in Box Elder and then pretty short distances in Weber, Davis, Morgan, and Summit).