Seeing the success of my post about the shortest state highways that go through multiple counties, I figured I might as well ask the inverse question: namely, what are the LONGEST state highways that are found in only ONE county?
If I had to guess, I would assume that most of them are out West, what with the huge counties in that part of the country (San Bernardino and Imperial counties in California come to mind in that regard).
Louisiana's is LA 103. 37.96 miles completely within St. Landry parish. It's another example of Louisiana highways that you would never drive end to end. It's in the shape of a U.
iPhone
Minnesota's looks to be MN 135, 36.16 miles all in St. Louis County.. MN 169, the vast majority of which is also in St. Louis County would beat it if it didn't clip into all of about 2 miles of Lake County at its eastern terminus (if this section gets turned back, it would pass MN 135).
Not sure if it's the longest overall, but Beltway 8 in Houston (Harris County) is the first that I can think of, at 88 miles long.
For New York state...
-Subject to confirmation, but I think the longest is NY 56, at 51.4 miles entirely within St. Lawrence County
-NY 12E, 36.1 miles entirely within Jefferson County
-NY 60, 33.2 miles entirely within Chautauqua County
Here in Monroe County, the longest is NY 383, at 18.7 miles.
Colorado's has to be CO 318. CO 318 is a 60 mile road entirely in Moffat county in remote northwestern CO, and it doesn't serve much purpose. It honestly shouldn't be signed as a state highway.
Looks like Utah's is SR 56, which spends all of its 61.5 miles within Iron County.
West Virginia: WV-26 runs 41.3 miles from US-50 in Fellowsville to it connection with PA-281, all in Preston County.
Not very long for Indiana. The southern IN 11 is 29.8 miles and entirely in Harrison County.
CT: CT 25 spends all of its 28.59 miles in Fairfield County (though it once extended into Litchfield and Hartford County). Just beats out CT 154 at 28.24 miles in Middlesex County
RI: RI 116 at 25.1 miles in Providence County
MA: MA 8 at 66.64 miles in Berkshire County. Just edges out MA 12 at 64.41 miles in Worcester County
ME: ME 161 at 83.03 miles in Aroostock County
VT: VT 102 at 43.75 miles in Essex County
NH: NH 118 at 37 miles in Grafton County
North Carolina: Not entirely sure, but it looks like NC-143 running 38.3 miles from NC-28 in Stecoah to the connection with TN-168, entirely in Graham County. Bonus, the last 18 miles is part of the Cherohala Skyway, which runs another 25 miles in Tennessee.
AR 72, about 42 miles long, entirely located in Benton County. I believe that's the longest one, although I didn't look that hard.
Washington's is SR 112, which runs for 61.31 miles entirely within Clallam County.
Quote from: webny99 on September 22, 2021, 09:33:38 PM
For New York state...
-Subject to confirmation, but I think the longest is NY 56, at 51.4 miles entirely within St. Lawrence County
-NY 12E, 36.1 miles entirely within Jefferson County
-NY 60, 33.2 miles entirely within Chautauqua County
Here in Monroe County, the longest is NY 383, at 18.7 miles.
Also NY 415, 42.8 miles in Steuben County
Quote from: jp the roadgeek on September 22, 2021, 10:42:57 PM
MA: MA 8 at 66.64 miles in Berkshire County. Just edges out MA 12 at 64.41 miles in Worcester County
Both of these go into other states.
Quote from: GenExpwy on September 23, 2021, 06:41:42 AM
Quote from: webny99 on September 22, 2021, 09:33:38 PM
For New York state...
-Subject to confirmation, but I think the longest is NY 56, at 51.4 miles entirely within St. Lawrence County
-NY 12E, 36.1 miles entirely within Jefferson County
-NY 60, 33.2 miles entirely within Chautauqua County
Here in Monroe County, the longest is NY 383, at 18.7 miles.
Also NY 415, 42.8 miles in Steuben County
Nice catch! Don't know how I missed that, as I even looked at Steuben County, but must have overlooked the I-86 corridor.
If we include provinces:
I think the longest King's Highway in Ontario in one county is Highway 105 in Kenora District at 173.5 km / 107.8 mi. For secondary highways, I think it's Highway 652 in Cochrane District at 149.9 km / 93.1 mi.
In Hawaii, HI 11 is 122.09 miles, and is entirely within Hawaii County.
It's more complicated in Alaska. The longest route in Alaska that doesn't cross a borough or census area boundary is AK 5, about 123 miles long. It's entirely within the Unorganized Borough (the vast area not yet included in any organized borough), and the Southeast Fairbanks census area thereof. If you limit to organized boroughs, AK 9 in the Kenai Peninsula Borough is about 36 miles long, and the discrete AK 7 segment in Haines Borough is about 43 miles long (the other three, shorter disconnected fragments of AK 7 are each in other boroughs).
The longest Alaska route that doesn't cross a borough boundary is AK 4, about 269 miles long, all of it within the Unorganized Borough. However, it is in three census areas (Chugach, Copper River, Southeast Fairbanks).
I think Virginia's is VA 234, which currently is 33 miles entirely within Prince William County, though in the past it has entered other municipalities.
California: looks like it's CA-247 in San Bernardino County, 78 miles from Barstow to Yucca Valley.
Honorable mention to CA-180, 122 miles, almost all in Fresno County, but nicks the corner of Tulare County for 5 miles.
Quote from: jlam on September 22, 2021, 10:00:04 PM
Colorado's has to be CO 318. CO 318 is a 60 mile road entirely in Moffat county in remote northwestern CO, and it doesn't serve much purpose. It honestly shouldn't be signed as a state highway.
CO64 would barely nudge it out if it didn't have the little bit that went up to Dinosaur.
If they ever got around to filling in the gap on CO90, it would be 89.8 miles all in Montrose County.
Chris
Quote from: cabiness42 on September 22, 2021, 10:39:00 PM
Not very long for Indiana. The southern IN 11 is 29.8 miles and entirely in Harrison County.
The southern SR 11 starts in Floyd County before heading south into Harrison County. Now nearby, SR 337 (the southern segment) does stay entirely in Harrison County and goes for 22 miles.
Quote from: 1 on September 23, 2021, 06:43:17 AM
Quote from: jp the roadgeek on September 22, 2021, 10:42:57 PM
MA: MA 8 at 66.64 miles in Berkshire County. Just edges out MA 12 at 64.41 miles in Worcester County
Both of these go into other states.
True, but the actual state-maintained highway is only in Massachusetts. MA 8 does not exist in Connecticut.
Quote from: Roadgeekteen on September 23, 2021, 09:04:40 PM
Quote from: 1 on September 23, 2021, 06:43:17 AM
Quote from: jp the roadgeek on September 22, 2021, 10:42:57 PM
MA: MA 8 at 66.64 miles in Berkshire County. Just edges out MA 12 at 64.41 miles in Worcester County
Both of these go into other states.
True, but the actual state-maintained highway is only in Massachusetts. MA 8 does not exist in Connecticut.
MA 63 exists in New Hampshire, though.
(https://www.alpsroads.net/roads/nh/misc/63.jpg)
(alpsroads. Obviously an error shield.)
In Georgia it appears to be SR 192 in Emanuel County, which is about 30 miles.
Iowa's longest is IA 62, which spends all of its 20 miles in Jackson County. Runners-up: IA 117 (18 miles in Jasper County), IA 415 (17 miles in Polk County), I-880 (17 miles in Pottawattamie County), IA 100 (16 miles in Linn County), and IA 127 (16 miles in Harrison County).
Quote from: tdindy88 on September 23, 2021, 08:55:19 PM
Quote from: cabiness42 on September 22, 2021, 10:39:00 PM
Not very long for Indiana. The southern IN 11 is 29.8 miles and entirely in Harrison County.
The southern SR 11 starts in Floyd County before heading south into Harrison County. Now nearby, SR 337 (the southern segment) does stay entirely in Harrison County and goes for 22 miles.
Indiana SR 69 is entirely in Posey County, and is 35.6 miles long. Is does share about 5 miles with IN SR 62 through Mt. Vernon.
For Michigan, I believe the answer is M-142 in Huron County at 39.2 miles
Nevada:
If we allow state highways that end at a state line and continue into the next state, it's Nevada 140 in Humboldt County, part of the Winnemucca to the Sea Highway, starting at US 95 and ending at the NV/OR border, where it continues as Oregon 140. That one measures 110.057 miles.
For highways that don't end at a state line, the winner is Nevada 305 in Lander County. That one runs 87.656 miles from US 50 near Austin to Nevada 304 in Battle Mountain.
I'm guessing that Illinois's answer might be Illinois 81, which is 25.78 miles long and completely within Henry County.
For Nebraska, I would guess this is NE 250, which is 48.64 miles and all in Sheridan County.
NJ...looks like it's NJ 17 at 27.2 miles, entirely in Bergan County.