At Lago Colorado, there's housing for the tour groups on the southwestern (So) end of the lake, and then again at the northwestern (No) corner, where there's a gate/fee station for entry into the park . When I came from the north, at the fee station they told me to go to the south housing - don't know if the north end was full or not - I just did what they said. So coming from the south, you may want to stop at the So unit and find out if there's space available before heading to the north end.

Essentially the huts/beds at both ends are there for the 4-wheel tour groups - bikers are unscheduled extras. Beds are 30 Bolivianos ($4 US) - essentially concrete platforms with a foam mattress on top, with about 6 heavy wool blankets. At that altitude (and being the old-ass I am), I couldn't breath under the weight of the blankets - had to sleep on top in my sleeping bag.

There's a park entrance a short distance from Hito Cajones if coming up from the south. I don't remember what the park fee was (50B?).

There's a small "store" at the So unit with some basic canned goods, pasta, drinks (cerveza and vino along with water and sodas). Its essentially a room with shelves where some woman lives with a child so don't look for a sign - you'll have to ask. I thought the fee I paid at the north gate included my lodging - so I tried to spend all my Bolivianos at her store for some , water and cookies that night since I knew I was leaving Bolivia the next day. The next morning when she came around to collect for the bed, I only had about 20B remaining. She wasn't thrilled about being 'stiffed' out of 10B.

There isn't any kind of currency exchange at the border near Hito Cajones - its simply a "middle of nowhere" immigration post. You probably want to try to find some currency exchange in S.P. de Atacama - get some Bolivianos for the park and the housing - and gas? Dollars are also accepted - can't say about Argentine or Chilean pesos.

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quastdog
Chiang Mai, Thailand