By 2003, rare native water lobelia had been documented along almost the entire shore of Mason Lake. A 1997 profile recorded specific conductance of forty to forty-five, characteristic of soft water; two years later, Secchi readings averaged twenty-one feet, phosphorus remained low, and the state classified the lake oligomesotrophic. In fall, coho pass through toward Schumacher Creek at the south end. Around them, 1,077 lakeside parcels fund a district through 2028 to control invasive weeds. Motorboats, water skiing, and jet skis share the lake, under county rules that slow traffic near shore, swimmers, launches, and nonmotorized boats and cap daytime speed elsewhere. A separate proposal in 2026 would bar wake-enhanced boats from every county lake except Mason and the dammed Lake Cushman. Commissioners subsequently created a temporary advisory committee to study the issue, leaving that exception under consideration rather than in force.
curator · lake-level · as of Sep 3, 2026
The facts
- Surface area 4 km² usgs-3dhp · lake-level · as of Jun 2, 2026
- Nearest town Forest Beach · 4.2 km osm-overpass · lake-level · as of Jun 2, 2026
- Bird species (within 25 mi) 208 ebird-api-v2 · lake-level · as of Jun 2, 2026
- Bird diversity index 0.89 ebird-api-v2 · lake-level · as of Jun 2, 2026
- Median home value $466,650 census-acs-2024-b25077 · block-group-level · as of Jun 2, 2026
- Water clarity Glass-clear curator · lake-level · as of Sep 3, 2026
- Night sky Darkest skies viirs-black-marble-vnp46a4 · lake-level · as of Sep 3, 2026
- Surroundings Exurban — scattered homes past the suburbs curator · lake-level · as of Sep 3, 2026
- Water origin Natural lake curator · lake-level · as of Sep 3, 2026
In more detail
- Climate
- four-season; cool winters (~41°F mean), mild summers (~63°F); ~60 in precip/yr curator · lake-level · as of Sep 3, 2026
- Public access
- Mason Lake has confirmed public access via Mason Lake County Park on the southwest shore near Grapeview, which includes a public boat launch. WDFW's fishing-location page corroborates a county-park boat launch and describes shoreline access as good but limited to the area around that launch. Fees/permits: Not confirmed. WDFW's page references a Discover Pass in the general context of state-managed fishing access, but Mason Lake's boat launch is Mason County-managed; no specific county launch fee was found in fetched sources.. Sources: wdfw.wa.gov (fetched 2026-07-12); masoncountywa.gov (fetched 2026-07-12). curated-web-harvest · lake-level · as of Jul 12, 2026
- Dogs and pets
- high — 37 dog parks within 25 mi (OSM); state rule: In Washington state parks, pets must be kept on a leash no greater than 8 feet in length (or otherwise physically restrained) at all times. Pets are prohibited on designated swimming beaches, except assistance animals for persons with disabilities. The State Parks director may designate specific off-leash pet areas, exempt from the standard leash rule. (WAC 352-32-060 (Washington Administrative Code, Parks and Recreation Commission, Public use of state park areas - Pets), fetched 2026-07-12); General Mason County parks material notes pets are banned at three named county facilities (MCRA, Sandhill County Park, Oakland Bay Historical Park) — none of which is Mason Lake County Park, so this does not apply here. No Mason Lake-specific pet rule found. curated-web-harvest · lake-level · as of Jul 12, 2026
- Property tax
- 0.73% ACS effective-rate proxy (2024 ACS 5-year; Mason County anchor: $3,006 median real-estate taxes paid ÷ $411,800 median owner-occupied home value; Washington proxy 0.81%, -0.08 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 built-out residential lake in a slow-growth corner of the county, with composition change rather than growth: the IAVMP (2003) records owners shifting from 50-plus percent full-time to under 20 percent across roughly 850 tax-roll parcels (now 1,077 in the LMD through 2028), and the flanking CDPs grew 954 → 991 (Grapeview, +3.9%) and 1,963 → 2,194 (Allyn, +11.8%) between the 2010 and 2020 censuses. Price is a level, not a slope — Union-Grapeview CCD $487,400 ±$32,630 and block group $466,650 (ACS 2024) — and the only dated trajectory is the assessor's countywide "approximately 7%–10%" on 2023 sales (Journal, 2024-10-10), not lake-specific; no permit series was fetched and the county has never regulated short-term rentals (review on hold). Hedges: the 2026 wake-boat proposal would concentrate the county's wake traffic here (a use pressure, not development), and Green Diamond's 48-acre camp, passed over by the county in March 2026, is listed for private sale.