1. This is the full tracking of your parcel:
Parcel No.RM706435296CN tracking result
2016-06-17 21:12:54.0 郑州帐单center received
2016-06-18 18:39:39.0 郑州帐单center customs scan
2016-06-18 19:07:08.0 leaving 郑州帐单center ，next station 郑州express
2016-06-19 09:38:24.0 郑州Transit Station export security scan
2016-06-19 11:22:40.0 郑州Transit Station export customs scan (domestic transit )
2016-06-22 02:22:44.0 Beijing Transit Station export security scan
2016-06-23 15:14:03.0 Beijing Transit Station export customs cleared
2016-06-23 20:40:00.0 arrive Beijing Airport
2016-06-23 20:46:50.0 leaving Beijing Airport going to next airport/seaport

2. This type of parcel can not be track in USA. China Post Airmail Parcel Estimate Arrival Time for USA can be found here:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

3. You can track it here also:
http://www.track-chinapost.com/track.php?code=RM706435296CN&fc=0

Hope this help.