US lakes & pondsUS lakes & pondsSurface area: The USGS National Hydrography Dataset outline (NHD Permanent ID 149338070).
The red circle marks Lost Lake.
Towns and counties: U.S. Census Bureau boundaries overlaid on the USGS lake outline (Washington: incorporated places touching the lake, otherwise the nearest one).
Official WDFW pages. Rules and fees change; check before you go.
Built only from the data on this page: official access lists, OpenStreetMap beaches and trails, campground listings, state and USGS invasive-species records. We don't rate crowds or water quality.
Stocked by the state: Rainbow trout (2015, 2016, 2017; 85,400 fish in all, fry included)
Source: Washington Department of Fish and Wildlife, WDFW Fish Plants data on data.wa.gov (releases into Lost Lake, Kittitas County, since 2015). See WDFW trout stocking reports. These are stocking records, not a full fish survey; other species also live here.
Numbers on the map match the list at rightbelow.
Shoreline: USGS National Hydrography Dataset (NHD Waterbody, Permanent ID 149338070), public domain. State outline: U.S. Census Bureau TIGERweb. Points: WDFW water access sites and OpenStreetMap boat ramps (ODbL). Interactive map: Leaflet with © OpenStreetMap contributors. Not for navigation.
We found 35 campgrounds and RV parks within 15 miles of Lost Lake, 5 of them within 5 miles. Distances are straight-line from the nearest point on the shoreline, so driving distance is longer.
Tent sites
Tent sites
Tent sites
Tent sites · Toilets
Tent sites
Electric hookups · RVs welcome · Dogs allowed
All campgrounds & RV parks in Washington
Green tent icons on the lake map mark campgrounds near the shore, and the interactive map shows the closest 12. Amenities are listed only where a source records them; call or check the campground's website before you go, since seasons and rates change every year.
Campground data: Recreation.gov (RIDB) · OpenStreetMap contributors (ODbL). Pulled Oct 12, 2026.
Live from the National Weather Service API for the lake's coordinates (47.3346, -121.4025). The nearest station may be several miles away. NWS forecast for Lost Lake. No live water-temperature sensor is shown because we haven't found a public one for this lake.
Based on solunar theory, an estimate. Major periods (about 2 hours) center on when the moon is directly overhead or underfoot; minor periods (about 1 hour) center on moonrise and moonset. The 0–100 activity score rises during those periods and gets a boost near sunrise and sunset and around the new and full moon. Weather, water temperature and pressure often matter more. Sun and moon times are calculated in your browser from the lake's coordinates with standard astronomy formulas, shown in PT (America/Los_Angeles), and accurate to within a few minutes.
1 public access site listed, 1 with a boat ramp or trailer launch.
| Site | Town | Owner | Type | Parking | Fee | Uses | Map |
|---|---|---|---|---|---|---|---|
| Lost Lake Boat Launch | — | — | Boat ramp (OpenStreetMap) · Yes ramp | — | — | Boating | 47.3340, -121.3940 |
WDFW water access sites and OpenStreetMap boat ramps (ODbL)
Fees, hours and rules change; confirm with the site owner before you go.
Lost Lake covers about 155 acres in Roslyn, Washington (Kittitas County).
WDFW fish stocking records lists Rainbow trout.
Yes. 1 public trailer launch is listed: Lost Lake Boat Launch. Check posted fees and parking rules.
Yes. We list 35 campgrounds and RV parks within 15 miles, 5 of them within 5 miles.
Lost Lake touches Roslyn in Kittitas County, Washington.
Know Lost Lake? Tell us about the launch, parking, where they're biting or anything a first-time visitor should know. Tips go privately to the LakeRipple editor; nothing is posted automatically. Helpful tips may be featured on this page (we'll use your first name only if you give one).
Straight-line distance between lake centers. All Washington lakes & ponds · All waters in Roslyn