There are over 30 fish species in Lake Roosevelt. When considering habitat conditions, managers tend to focus on the needs of kokanee and redband/rainbow Trout. These fish are native to the area, which means we've been here for centuries.

The temperatures we prefer vary between 5 and 17º Celsius (41-62.6ºF) for kokanee, and 12 to 18º Celsius (53.6-64.4ºF) for rainbow trout. Thankfully, temperatures in the lake generally fall in this range. The exception is the summer months. Because the lake is flat and not flowing rapidly, temperatures (particularly at the surface) can heat up beyond what's good for us. In August, the average surface temperature in Lake Roosevelt is about 21º Celsius (69.8ºF).

To adjust for these conditions, we can swim deeper than we normally would. For those of us looking to meet our food and oxygen needs, managers and scientists are monitoring how this adjustment affects our health.