In reply to GW4OKT:
When SOTA first started activators used the traditional QRP frequencies, but the QRP ops soon compained that whilst SOTA activators were usually using QRP the chasers certainly were not and this resulted in a lot of deliberate QRM.
The CW SOTA ops then moved a couple of KHz away from QRP spots, so we tend to use 3558, 7032, 10118 14058, 18086, 21058 and 28058 KHz.
A CW chaser with one receiver will monitor 7032 KHz, with 2 receivers he will also monitor 10118 KHz. There will not be anyone monitoring higher than this so you will need to post an alert or self spot. If you do this it will not matter which frequency you use.