> Canonical: https://marylandparks.org/parks/st-marys-river-state-park > Content revision: 2026-10-15T16:46:39.199Z [State parks](https://marylandparks.org/types/state-park)[St. Mary’s](https://marylandparks.org/counties/st-marys) # St. Mary's River State Park St. Mary’s · Maryland Department of Natural Resources PLAN YOUR VISIT ## The practical details. **Managing agency**: Maryland Department of Natural Resources [Official park information](https://dnr.maryland.gov/publiclands/Pages/southern/stmarysriver.aspx) We have not yet verified hours, entry fees, accessibility details. Confirm these with the managing agency before traveling. Check notice timestamps and official updates. Conditions can change between source checks. ## Weather & forecast National Weather Service · [Official forecast ↗](https://forecast.weather.gov/MapClick.php?lat=38.26362&lon=-76.54147) ## About St. Mary's River State Park Site 1 (Lake) May through September 6:00 a.m. to sunset October through April 7:00 a.m. to sunset Site 2 (Wildlands) Sunrise to sunset Please note that the gate is automated and will accept credit or debit cards only, as well as the swipe card issued by the park. Situated at the northern end of the St. Mary's River watershed, St. Mary's River State Park is separated into two areas, Sites 1 and 2. The Site 1 area holds the 250-acre St. Mary's Lake. Located along Maryland Route 5, between Leonardtown and Great Mills, at the end of Camp Cosoma Road, the area has become a popular freshwater fishing spot. This area has been improved by a modern comfort station, picnic tables, playground, boat launch ramps and a large gravel parking lot. Leashed pets are allowed in the state park. The day use service charge for Site 1 is credit-card only, $3/vehicle for Maryland residents. Out-of-state residents add $2. Charges are collected at the automated gate system at the entrance. Passholders (Maryland Passport, Golden Age and Universal Disability) may contact the park office at 301-872-5688 or by email ([email protected]) to receive an additional swipe card that allows free entry through the automated gate system located at the Lake Area of the park. ## Find your way. Map points represent park land, not verified visitor entrances. Follow the managing agency’s entrance directions. Tiles © OpenStreetMap contributors. This point represents park land, and may not be a public entrance. Follow official entrance directions. [Official visitor information & directions ↗](https://dnr.maryland.gov/publiclands/Pages/southern/stmarysriver.aspx) ## Read before you roam. [THE FIELD GUIDE ### How to read park closures & visitor notices Check the affected area, source, dates, and last verification before planning a Maryland park visit. Read the guide](https://marylandparks.org/guides/understanding-park-notices)[THE FIELD GUIDE ### Pests, treatments & Maryland park visits Understand pest notices, treatment schedules, and the difference between regional guidance and a documented park impact. Read the guide](https://marylandparks.org/guides/pests-and-park-visits)[THE FIELD GUIDE ### Plan a Maryland park day A practical sequence for choosing a park, checking access, reading the forecast, and finding official visitor information. Read the guide](https://marylandparks.org/guides/planning-a-maryland-park-day) ## Sources & verification Park facts and notices are checked separately. Missing facility information does not mean a facility is absent. Official visitor page checked Oct 15, 2026. - [Maryland state park directory](https://dnr.maryland.gov/publiclands/Pages/parkmap.aspx) · Oct 15, 2026 - [Maryland DNR lands](https://mdgeodata.md.gov/imap/rest/services/Environment/MD_ProtectedLands/FeatureServer/0) · Oct 15, 2026 [Suggest a correction](https://marylandparks.org/about#corrections) · [Markdown version](https://marylandparks.org/parks/st-marys-river-state-park.md) ## Nearby parks. Within 35 miles in a straight line. Travel distances and entrances vary. [All parks](https://marylandparks.org/parks) [St. Mary’s ### Salem State Forest Maryland Department of Natural Resources](https://marylandparks.org/parks/salem-state-forest) [St. Mary’s ### Mcintosh Run Wildlife Management Area Maryland Department of Natural Resources](https://marylandparks.org/parks/mcintosh-run-wildlife-management-area) [St. Mary’s ### Newtowne Neck State Park Maryland Department of Natural Resources](https://marylandparks.org/parks/newtowne-neck-state-park)