Marsh Lake is a popular fishing destination in Wyoming, USA, known for its abundant fish species and beautiful scenery. The lake is located in the Bridger-Teton National Forest and is a part of the Gros Ventre River drainage system. Here's a quick fishing guide summary of the area:

Fish Species:
The Marsh Lake is home to various fish species, including rainbow trout, brown trout, lake trout, cutthroat trout, and brook trout. Rainbow trout is the most common fish species in the lake, followed by brown trout and cutthroat trout.

Nearby Activities:
Apart from fishing, the Marsh Lake area offers several other outdoor activities, including hiking, camping, hunting, wildlife viewing, and photography. Visitors can also explore the nearby Teton National Park and enjoy activities like kayaking and river rafting.

Fishing Tips:
To catch the most fish, anglers should try using dry flies, nymphs, or streamers. The best times for fishing are early morning or late afternoon. Anglers should also consider using a boat to access the deeper waters of the lake. And, as always, make sure to check local regulations and obtain necessary permits before fishing.

Best Time of Year and Average Temperature:
The best time to visit Marsh Lake for fishing is during the summer months (June to August), when the water temperature is optimal for trout. The average temperature during this time ranges from 60°F to 80°F. It's recommended to avoid visiting the area during winter as the lake is often frozen, and fishing is not possible.

Overall, Marsh Lake is an excellent fishing spot for anglers looking to catch different trout species, and the nearby activities make it a great destination for a weekend getaway.