About 3,400 acres of trout water ringed by red clinker beaches, with the Bighorn Mountains on the western skyline and historic Buffalo 8 miles down the road.
Live from the National Weather Service, Buffalo airport station (KBYG), south of the lake, observed Oct 28, 8:30 AM MT. Elevation (about 4,570 ft) and max depth (120 ft): Wikipedia and Johnson County.
Acres and average depth: [Wyoming Game and Fish]. Max depth and distance: [Johnson County, 2]. Exit: [I-90 exit list]. Elevation: [Wikipedia]. Clinker geology: [USGS]
May to JuneDive-site notes say the lake usually runs deepest in May. Boat inspection season starts March 1, so out-of-state boats need a check before they launch.
July to AugustHighs in the low 80s in Buffalo, cool nights, long evenings on the water. Rodeo week in Sheridan and Longmire Days in Buffalo fill beds early.
September to OctoberThe summer crowd thins out and the grass goes straw-gold. September still averages highs around 71 in Buffalo. The lake usually sits lowest by October.
When it freezesWhen the ice is safe, anglers walk out for trout, perch and walleye. The Rotary Club of Sheridan held its fifth ice fishing derby here in February 2025.
Weather: [Buffalo normals 1991-2020]. Water level: [PADI dive-site notes]. Inspections: [Game and Fish]. Derby: [The Sheridan Press]
Wake up near the water. Owner-listed cabins and homes in Buffalo, Story, Banner and Sheridan, all within about half an hour, plus lakeside campsites on the south shore.
Owner listings open this season. Own a cabin, home or lodge near the lake? List it free.
Every boat brought into Wyoming from March 1 to November 30 must be inspected before it launches. Nearly every boat, kayaks and canoes included, needs a current AIS decal; small inflatables and paddleboards are the exception. [Game and Fish, 2]
One wearable life jacket per person aboard. Kids 12 and under wear theirs while underway. That includes kayaks and paddleboards. [Game and Fish, 2]
DEQ issued a bloom advisory for the lake in mid-July 2026. On July 24 it reported no toxins and the lake stayed open. Avoid scum, rinse off, keep dogs out of it. [Wyoming DEQ, 2]
Mikesell-Potts is first come, first served, paid on the honor system, with no drinking water or dump station. Bring your own water. [Johnson County]
Monument Point is open all year with a concrete ramp and dock, and Mikesell-Potts keeps one restroom open through winter. [Sources, 2]
No one certifies the ice. Drill and measure it yourself, every trip, every few steps from shore. Ice fishing guide
Quick answers, each backed by the agency that knows. More on the full FAQ.
In Johnson County, Wyoming, about 8 miles north of Buffalo off I-90 Exit 51. It is not De Smet, South Dakota, which shows up in a lot of searches.
Wyoming Game and Fish puts it at about 3,400 surface acres with an average depth of 69 feet. Johnson County lists the maximum depth at 120 feet.
Game and Fish lists walleye, rainbow, brown, lake and cutthroat trout, kokanee salmon, yellow perch and rock bass. Rainbows carry the fishery. In October 2026 Game and Fish also found an illegally released northern pike: if you catch one, kill it, keep it and call (307) 672-7418.
Yes. The county-run Mikesell-Potts Recreation Area on the south shore has more than 60 sites at $15 a night and 8 electric sites at $20, first come, first served, with no drinking water or dump station.
Wyoming DEQ issued a harmful algae bloom advisory for the lake in mid-July 2026. On July 24 it said no toxins had been detected and the lake stayed open. In summer, check WyoHCBs.org before you swim and keep dogs out of scummy water.
Search for Lake DeSmet lodging and you often land in De Smet, South Dakota. List your cabin here free, feature it, or have Wyo Stays manage it for you.
Ice-on and ice-off notes, what Game and Fish is saying about the fishery, events worth the drive and new places to stay. One email a season.
