Fishing by the Lake Postcard

One of five promotional postcards sent to those who pre-ordered the Pokémon Crystal game. Illustrated by Keiko Fukuyama and is part of the "Set A" of the postcards¹.

Shuckle is found just to the left of the bridge.

I saw this one called Fishing by the Lake at The Art of Pokémon², I don't think it's official but I liked it!