Boundary County

All Hazards Mitigation Plan

Section 3

Jurisdictional Profile

 Location   Boundary County, the northernmost county in Idaho, lies at the top of the “Idaho Panhandle,” almost exactly between 48 and 49 degrees latitude and between 116 and 117 degrees longitude.  On its east side, the county borders Montana. Along the northern border is British Columbia, Canada, to the west is the state of Washington, and to the south lies Bonner County, Idaho.

Map 3-1: Boundary County, Idaho

Topography   Steep mountains and two major rivers dominate the landscape of the county.  To the west, the Selkirk Mountains rise to elevations of more than 6000 feet.  To the east, the Purcell Mountains lie on the boundary with Montana.  With headwaters in Canada, the Kootenai River flows south to Libby, Montana, then west to Bonners Ferry and back north into Canada at Port Hill.  Also with headwaters in Canada, the Moyie River flows south and enters the Kootenai River at Moyie Springs.

Geologic History "The Pleistocene event that left the greatest visible impact on Idaho was glaciation" (Ross and Savage, p.81).  Glaciers left typical outwash benches and plastered glacial debris along the face of the Selkirk and Purcell Mountains.  The Purcell Trench, which runs north and south through the center of the county, was formed during the glacial period some 32,000 to 80,000 years B.P. by continental glaciers.  Thus, the Kootenai River valley (in the Purcell Trench) is a wide, U-shaped valley from Canada to south of Bonners Ferry.  This geologic history contributes to the natural hazards that have created problems since settlement. 

Climatology   “North Idaho is in a major storm track, in addition to being in a position to receive large quantities of moisture carried inland from the Pacific Ocean" (Ross and Savage, p. 195).  Annual precipitation ranges from about 20 inches in the valley bottoms to over 40 inches at higher elevations.  This precipitation is evenly divided between rain and snow below 3000 feet.  Above this elevation, most of the moisture comes as snow (Ross and Savage, p. 195).  These conditions lead to a fairly high frequency of weather-related hazardous events. 

Because of the relatively abundant annual precipitation, Boundary County lands produce good agricultural crop yields and highly productive forests.  Particularly in the forests, large quantities of biomass are grown annually.  Wildfire has been the primary recycling agent of this biomass for thousands of years due to several months of hot and dry summer weather and associated thunderstorms.

Land Area  Boundary County has an area of 1,269 square miles of land, or approximately 1.5 percent of the land base for the State of Idaho (82,747sq. mi.).  Its size puts Boundary County near the median of county sizes in the state, with 23 counties being smaller and 20 counties being larger in area. 

Land Ownership and Use  In Boundary County, land ownership is composed of 61.4 percent federal lands, 13.2 percent state lands, 26.5 percent private lands, and 0.2 percent city and county property.    Boundary County has approximately 25 percent of its land open for development.  The county is seeing an increase in new development, sub-divisions, and businesses.  For example, housing development has occurred in Marx’s Addition, which was annexed into the City of Bonners Ferry.  The county anticipates that future land use percentages will change.

This land ownership situation provides a relatively small tax base, and consequently, fewer public services and a lower level of infrastructure.  A small population and attendant small tax base puts the county at a disadvantage in being able to respond to an event, particularly a larger scale event.

The following tables show current ownership percentages and land use categories within the county:

Table 3-1.  Land Ownership

Land Ownership

% of  Jurisdiction








   0 .2



Table 3-2.  Current Land Use Categories

Land Use Categories

% of  Jurisdiction

Urban Land










Table 3-3.


Percent of Total Land Ownership in Boundary County




Population   Boundary County is one of the least densely populated counties in the state, with 7.8 residents per square mile (US Census, 2000).   The population in Boundary County increased from 7,289 residents in 1980 to 10,085 people in 2002.  The median age rose from 29.3 in 1980 to 38.3 in 2000.  From 1990 to 2000, the county experienced an 18.5 percent increase in population. 

Much of this population has settled in the communities of Bonners Ferry (county seat), Moyie Springs and Naples.  At least 56 percent of the population lives outside of city limits.  Approximately 80 percent of the county population lives within three miles of the transportation/utility corridors that are described later in this report.  Kootenai Tribe of Idaho has a small residential community at what is commonly called "the Mission."  The Mission is on 18 acres adjacent to the banks  the Kootenai River.

Population of Incorporated Communities:

City of Bonners Ferry     2,647

City of Moyie Springs        656

Non-Incorporated Communities: [Population figures are unavailable]             




Map 3-2

 Boundary County, Idaho