Blue Hole

Santa Rosa sits on the Pecos where old Route 66 and I-40 run along the edge of the plains, and it calls itself the City of Natural Lakes for the water that rises out of the limestone here. The best known is the Blue Hole, a round pool ringed with sandstone ledges, its water so clear the bottom shows 81 feet down. Below the surface it widens like a bell. A cave system near the bottom pushes in about 3,000 gallons a minute, enough to replace the whole pool every few hours, and holds it at about 61 or 62 degrees all year. It was once used as a fish hatchery.

In summer it is a swimming hole, and people jump from the ledges ten feet above the water. The rest of the year it belongs to scuba divers. There are few inland dive sites in the Southwest, and classes come from Texas, Colorado, Oklahoma and Kansas to train here; winter is the busiest season.

The pool sits at about 4,600 feet, so every dive in it is an altitude dive. The thinner air above means a dive to the bottom has to be planned as if it were deeper than it is, and divers heading west toward Albuquerque wait several hours before driving over the pass of more than 7,000 feet on the way.

Diving needs certification and a permit from the city, sold by the week, and a dive shop beside the pool fills tanks and rents gear.