LOCATION OF THE ADA COUNTY/BOISE COUNTY LINE
IN THE STATE OF IDAHO
by David Couch, PLS
For the past 140 years there has been a county line common to Ada and Boise Counties in the State of Idaho. Although important from a county jurisdictional standpoint, the location of the boundary line between the counties has not had much importance attached to it by the private sector. Therefore, it has been relatively untouched, and unlocated for the majority of that time. With land development looming in the near future, we now need to know precisely where the location of the common county line is, on the ground. Applications for development must be filed in the correct county and taxes assessed accordingly. The following represents some of the history that we have found and the work progress on the location of that line to date.
The Ada County/Boise County line lies in the most rugged part of Ada County. The common line starts at the confluence of the Boise River and Mores Creek, now underwater in the Lucky Peak Reservoir. The line continues on a northwest bearing across the top of the first ridge and down across the reservoir in the first mile. It then proceeds some 21 miles across the top of the foothills, near the treeline, and then down to Highway 55 and across the highway to the township line, and the south boundary of Gem County. That part of the line near Highway 55 is across private land formerly owned by Spring Valley Ranch. Where the line meets the township line there are actually two township corners, 20 feet apart. Originally, this county line also continued another 11 miles along the northwest bearing to the Payette River, below Black Canyon Dam, near the town of Emmett. The 11 mile line was eliminated when Gem County was created in 1915.
The following is some of the chronological history of the common boundary between Ada County and Boise County, Idaho. Efforts have been made by the Assessor's Office staff, Jack Clark and Sheldon Bluestein, to research historical information and records in the various courthouses and in some cases, private information, pertaining to the location of the county boundary line between Ada and Boise Counties.
An actual boundary survey was ordered by the Legislature in 1883 to define the boundary line and set monuments at regular intervals. No survey notes or plats of that survey have been found to date even though they were supposedly recorded in the recorder's office.
Early on I speculated that the county boundary line was monumented with marked stones at milepost intervals. This was based on earlier experiences with surveys on the Lemhi Indian Reservation Boundary Lines in Lemhi County. I envisioned that we were looking for stones with an “A” chiseled on one side and a “B” on the other side. I also believed that the stones would be marked with a milepost number.
The surveying research was conducted by the Ada County Surveyor's Office, John Priester and myself previously. Now with the addition of new staff members, Glen Smallwood and Jerry Hastings, we hope more manpower will help to uncover the location of the line. Preliminary latitudes and longitudes have been determined for the mileposts along the twenty one miles of line by various methods. One method is using the National Geographic software Topo! for the State of Idaho and setting waypoints at one mile intervals along the line. These waypoints are then loaded into the Garmin handheld GPS receiver for search coordinates to look for on the ground. This method works quite well on section corners, quarter corners, and other locateable features on the map. So far, all the locations searched for have not turned up any other mileposts..
WHAT THE LEGISLATIVE MANDATE SAID
In 1883, some 19 years after Ada County was formed, the Idaho Territorial Legislature mandated a survey of the line between Ada and Boise Counties. It’s purpose was:
- To establish and better define the boundary line between Ada and Boise counties...
- Boards of County Commissioners of Ada and Boise counties respectively, shall, acting conjointly, cause said line to be accurately located and defined, by the erection of proper monuments and land marks at intervals along said line.....
- Such location and survey shall be completed to the first day of July, A.D. 1883, and a map thereof and copy of the field notes presented by the surveyors of the line to the chairman of the Boards of Commissioners of each of the counties of Ada and Boise, together with proof of the performance of the survey, in such manner as shall have been agreed upon.
Records show that T.W. Randall was paid $250.00 by Ada County on July 7, 1883 for the survey of the county line. Records also show that he was paid $250 by Boise County.
To date, no record of the any survey field notes and map have been found for this county line survey. Searches have been made for these documents in Gem, Canyon, Boise, and Ada County. Some map documents have been found that show mileposts with roman numerals shown alongside that indicated survey tie information from the township corner. Highway plans, Bureau of Reclamation surveys and old maps have shown some general locations of the county line. Almost always the line is shown on maps as an indefinite line.
For the current report of the survey of the Ada County and Boise County Boundary Line (May 2005) in either a Word doc or .pdf file by David Couch.
THE STATE CODE GAP
In researching the descriptions of Ada and Boise Counties in the Idaho State Code, a gap in the descriptions was discovered by Jack Clark, PLS, of the Assessor’s Office. The Ada County line description was described as being on a bearing of N. 44° 38’ W. until it intersects with the township line. The Boise County line description goes to a single point, which was the township corner. This left a gap in the descriptions of some 1500’ at the north end of the county lines. To correct this gap in the description, the Board of Commissioner’s of both Ada County and Boise County met to determine a solution to the problem. Both board’s agreed to use the Ada County description for the common boundary line. That meant the Boise County description in the Idaho Code needed to be changed to agree with the Ada County line. This was accomplished in the 2004 Legislature and will be effective on July 1, 2004. That still leaves the line to be identified on the ground.
THE FIRST STONE
Jack Clark pursued the notion that one of the families of the old owners of the property, near the confluence of the Mores Creek and the Boise River (now under the Lucky Peak Reservoir) was still alive and worth chasing down. Using the deeds and making several phone calls, he contacted one of the members of the family living in Owyhee County and discovered that they had an old stone, that was removed from their property when they left. They were told to remove all of their possessions when they left, before the reservoir was filled behind the dam. The father had an engineering interest and evidently wanted the stone to take with him. Jack asked the people if he could have the stone as it was of great interest to those of us researching the county line. The stone had a perfectly scribed “A” on one side and “B” on the other side. There are several theories about this stone. I believe this stone is the initial point stone, which was set near the confluence of the rivers and was the starting point for the survey of the county line.
THE SECOND STONE
After several unsuccessful reconnaissance trips in searching for that first stone that was in place, John Priester and mysef decided one afternoon in March to search for monuments at the north end, near the two township corners for any sign of the corners and line. Our search took us to the two township corners where we discovered an extra stone, twenty feet to the east, that had a “CC” chiseled on the side. That makes for three corners in a row, each twenty feet apart, that may have future implications. Proceeding the 1500 feet to the west and 400 feet southeast, we began to search for all the stones. As I was searching higher on the hillside, John hollered out that “I have a B”. I said do you have an XXI? A minute later he hollered “Yea, I’ve got an “XXI” and an “A”. It looked beautiful to the surveyor’s eye and was the first stone found on line. This will start to crack the puzzle of where the line is on the ground. With the found stone plotted on the map, we now have a new line to search for between the old Boise County line and the new agreed upon Ada/Boise County line.
THE TOTAL DISTANCE
Finding the number XXI (21) milepost stone means we now have a total distance between monuments of around 21 1/2 miles. This makes the search areas for the mileposts somewhat interesting with a half mile floating around. But in actuality, it only means that each mile is 5365 feet long, easily within the tolerance of chaining across this very rugged terrain. Only time will tell, as we uncover more monuments, if the ½ mile is a single bust in distance or accumulation over the total 21miles. It certainly could be the chaining error with less than 100 feet error for each milepost.
Current Report of the Survey of the Ada County and Boise County Boundary Line
An updated report, May 2005, in either a Word .doc or .pdf file by David Couch.
During the summer and fall of 2006, the surveying division is planning to post and mark the county boundary line with white fiberglass posts that will identify which county you are in. The posts will be set in a stationing format that will be more intervisible and useful to the general public. Setting them on top of hills and where it crosses the roads/creeks, etc will be places of more practical use.
SIMILAR COUNTY LINE SURVEY IN MISSOULA COUNTY/DEER LODGE COUNTY, MONTANA
Gary Little, Florence, Montana, has a survey of the county line between Missoula County and Deer Lodge County in Montana that is very similar to the Ada/Boise County Line. Both county lines were surveyed in 1883 and filed in two counties, but the survey notes and the survey plats have not been found to date in both cases. A newspaper article about the survey of the 38 mile county line was written in 1884, by a writer from the Missoulian newspaper, who accompanied the survey crew during the survey. It provided several clues as to the location of some monuments and was valuable in recovery efforts. Gary has found some 20 monuments to date and they were not set at the one mile intervals as was presumed, but rather at 1,200 ft to 3,000 ft spacing at prominent topographical places.
His e-mail about the project:
The 1884 newspaper article about the 1883 county boundary line survey:
Pictures of three monuments found: 1, 2, 3.
Updated: Tuesday, July 25, 2006