Student pilot reported a NMAC while flying solo cross-country flight.

Narrative

The weather as I recall was clear and winds were fairly calm; visibility was unlimited. I was a student pilot flying with 31 hours total time all in Aircraft X on on my first solo cross country from ZZZ to KLS via a preplanned route using pilotage and dead reckoning. I'd turned established my self on a magnetic course of 175º and was at an altitude of 3;500 ft MSL (just at the bottom of the established VFR cruising altitudes). I had established my self on heading a few minutes prior; scanned ahead for traffic; and checked my position on my chart when I looked up to scan again for traffic ahead when I saw a low wing aircraft in my windscreen head on at about 5 feet higher in altitude than I was. The aircraft was not moving in my windscreen; and by my estimation I may have been obscured by his cowling. As soon as I saw the aircraft I executed a immediate -0.5 G or greater dive into a diving right turn of approximately 1.5+G or greater. At the end of the turn I was established on an approximate course of 345º magnetic. By that point the other aircraft had passed me and was on his same heading at altitude (He had taken no evasive action). He was significantly faster than me; so some distance had already built between us. I maintained the same heading as him momentarily with the intent of reporting the near miss to ATC but I was unable to make out a tail number; Seattle approach coverage and radar coverage were spotty at my altitude; owing surrounding hills. As a result no report was filed with ATC at the time. The incident took place in the late morning or early afternoon.In my opinion contributing factors were: 1. The topography of the area meaning VFR traffic is funneled down the North-South Valley between OLM and KLS. 2. The closeness of selected course to a magnetic course of 180º where VFR altitudes change. 3. The low altitude of the flight. 4. Poor radar coverage; and ATC radio coverage resulting in a the unreliability of radar services at altitudes less then 6;000 ft. MSL.