Tenmile Lake begins with a dam made of sand. Dunes pressed across Tenmile Creek sometime between 18,000 and 6,000 years ago; no engineered dam or weir followed. The lake still rises and falls with rain and what its sandy outlet will pass. Its gauge read 5.78 feet on August 25, 2026. By 2019, the lake association had recorded five extremely low summers, with damaged boats and limited access to the canal. The state's boating rule creates four pockets of slow water — at the swim beach, ramps, creek entrance, and canal. Beyond them, the open water hosts bass tournaments on many weekends. The same August gauge caught another kind of summer pressure: 71-degree water under 60-degree air. Tenmile averages about five meters deep and ranges from meso-eutrophic to eutrophic. Toxic blooms have been documented since 1997. A 2019 Wulfy Beach sample measured 15.14 micrograms of microcystin per liter; a precaution at 2.53 had remained in place since June 2026. Monitoring found that Microcystis biomass and toxin levels tended to follow water temperature.
curator · lake-level · as of Sep 3, 2026
The facts
- Surface area 4.6 km² usgs-3dhp · lake-level · as of Jun 2, 2026
- Nearest town Lakeside · 2 km osm-overpass · lake-level · as of Jun 2, 2026
- Bird species (within 25 mi) 179 ebird-api-v2 · lake-level · as of Jun 2, 2026
- Bird diversity index 0.78 ebird-api-v2 · lake-level · as of Jun 2, 2026
- Median home value $358,350 census-acs-2024-b25077 · block-group-level · as of Jun 2, 2026
- Water clarity Moderate curator · lake-level · as of Sep 3, 2026
- Night sky Darkest skies viirs-black-marble-vnp46a4 · lake-level · as of Sep 3, 2026
- Surroundings Rural — open country, few close neighbors curator · lake-level · as of Sep 3, 2026
- Water origin Natural lake curator · lake-level · as of Sep 3, 2026
In more detail
- Climate
- temperate year-round; mild winters (~47°F mean), cool summers (~60°F); ~62 in precip/yr curator · lake-level · as of Sep 3, 2026
- Public access
- Public access is strong via a single county-run facility. Coos County Parks & Recreation operates Tenmile Lakes Park in Lakeside with four boat ramps, accessible docks and kayak launch, a fishing dock, and a designated swimming/wading area. The Oregon State Marine Board's statewide access report independently confirms this ramp as an open public access point. Fees/permits: Camping/RV and picnic-gazebo reservations require 24-hour advance notice (541-396-7755); no day-use boat-launch fee was stated on the official county or Marine Board pages.. Sources: co.coos.or.us (fetched 2026-07-12); oregon.gov (fetched 2026-07-12). curated-web-harvest · lake-level · as of Jul 12, 2026
- Dogs and pets
- medium — 0 dog parks within 25 mi (OSM); state rule: Oregon state parks require pets to be under physical control on a leash no more than six feet long at all times, except in park-manager-designated off-leash areas; pets are prohibited on beaches adjacent to designated swimming areas. (OAR 736-010-0030 (Domestic Animals) — general Oregon State Parks rule, fetched 2026-07-12); No lake-specific pet rule (off-leash area, beach pet ban, or exception) found on the Coos County park page or the state Marine Board access page. Tenmile Lakes Park is county-managed, not a state park, so the statewide OAR leash rule does not directly govern it; a general county park leash policy likely exists but was not located via a primary source (only low-quality directory sites referenced Coos County dog-park leash norms, and those were excluded as non-primary). curated-web-harvest · lake-level · as of Jul 12, 2026
- Property tax
- 0.68% ACS effective-rate proxy (2024 ACS 5-year; Coos County anchor: $2,284 median real-estate taxes paid ÷ $337,800 median owner-occupied home value; Oregon proxy 0.81%, -0.14 percentage points). census-acs-2024-property-tax · county-level · as of Dec 31, 2024
Where it’s heading
Stable hand-rated for v0.1 · lake-level · as of Sep 3, 2026
Stable by the mini-pass criterion — a small retirement-and-recreation town with no documented growth vector: Lakeside 1,699 → 1,904 between the 2010 and 2020 censuses (+12%, Wikipedia/Census), median age 60.7 with 40.4% over 65, 1,068 housing units at 18.1% vacant, and a city that "does not receive money from property taxes except for the library", funding itself on transient (RV and motel) tax, hangar rents and grants (City of Lakeside). Price is a level, not a slope — ACS 2024 block group $358,350, Lakeside city $304,900 ±$37,425 — and no dated trajectory was fetched (Redfin/Zillow refused; the search-index figures conflict and are recorded as extractions only). Hedges: the decade's +12% is real but the pressure signals cut the other way — five extremely low summers by 2019 pushing recreation to Eel Lake (Heley), a standing cyanobacteria record since 1997, and an RV resort the reviews call run down; nothing on the sheet documents permits or new subdivision.