I've swam in Alta and MIrror Lake and I actually think Alta is nicer. You are in for a treat.

Swam there this past Sunday and the water was great - it was a bit chilly, but nice and clear. In the shallower areas near shore you are able to see the lake weeds very clearly (I'd say at maybe 2-3 meters). The water can get a bit choppy in higher winds, but the early start should avoid this for the full distance.

never swam in Mirror but Alta is waaaay clearer than TTL. very enjoyable swim. one of the most picturesque in all my racing experiences. didn't have any visibility issues. the sun does come over the mountains on the second loop. from what I remember it just effected me for the short section heading east around the first turn buoy. but something to consider.

Awesome! Thanks everyone!

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Honestly it’s a stunning beautiful swim. Much better for the swimmers than the spectators!