Trevor Potter, a former federal election commissioner who now runs the Campaign Legal Center, a watchdog group that advocates for more restrictions on money in politics, reviewed the documents found in the boxes.
"This is the sort of information that is, in fact, campaign strategy, campaign plans that candidates cannot share with an outside group without making it coordinated," Potter said.
"You need to know more, but certainly if I were back in my FEC days as a commissioner, I would say we had grounds to proceed with an investigation and put people under oath and show them these documents, and ask where they came from and where they were."
After the 2008 election, Montana started investigating whether WTP should have disclosed its donors.
The inquiry progressed slowly until 2010, when a former WTP contractor handed over internal fundraising records, saying she was worried about what the group was doing.
The documents showed that the group raised money specifically by telling people and corporations that they could give unlimited amounts in secret.
"The only thing we plan on reporting is our success to contributors like you who can see the benefits of a program like this," said one document, a 2010 election briefing to read to potential donors. "You can just sit back on election night and see what a difference you've made."
A target list of potential donors included an executive at a talc mine, the Montana representative of an international mining group and a Colorado executive for a global gold-mining company.
One note about a potential donor advised: "Married rich, hard to get a hold of. Have a beer with him." Another said: "Owns big ranch, signed a hit piece I wrote on cty cmms'r last year (don't mention), should give $$ $10,000 ask."
Other notes suggested that solicitors "See Christian" or "Talk to Christian," apparently references to LeFer.
The documents cited the group's success in 2008, saying in a confidential grassroots membership development proposal that 28 Montana state legislators "rode into office in 100% support of WTP's responsible development agenda."
By 2010, the partnership was active in state races in Montana and Colorado.
That October, Montana authorities said Western Tradition Partnership had violated campaign-finance law and should be fined. They said the group's purpose in 2008 was "not to discuss issues, but to directly influence candidate elections through surreptitious means."
The Montana investigation also said the evidence was overwhelming that WTP had established the Coalition for Energy and the Environment, known as CEE, as a "sham organization" to act as a front for expenditures actually made by WTP.
But the investigation also found that "sufficient evidence has not been disclosed to establish coordination between WTP/CEE and any candidate. Concern and healthy skepticism is warranted, however."